AMT

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): February 24, 2026

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

222 Berkeley Street Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 3.625% Senior Notes due 2032AMT 32BNew York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On February 24, 2026, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the year ended December 31, 2025. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated February 24, 2026 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): October 28, 2025

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 3.625% Senior Notes due 2032AMT 32BNew York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On October 28, 2025, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended September 30, 2025. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated October 28, 2025 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): July 29, 2025

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 3.625% Senior Notes due 2032AMT 32BNew York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On July 29, 2025, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended June 30, 2025. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated July 29, 2025 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): April 29, 2025

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On April 29, 2025, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended March 31, 2025. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated April 29, 2025 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:April 29, 2025By:/s/ Rodne

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): February 25, 2025

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On February 25, 2025, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the year ended December 31, 2024. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated February 25, 2025 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): October 29, 2024

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On October 29, 2024, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended September 30, 2024. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated October 29, 2024 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to b

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): July 30, 2024

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 3.900% Senior Notes due 2030AMT 30DNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange 4.100% Senior Notes due 2034AMT 34ANew York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On July 30, 2024, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended June 30, 2024. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated July 30, 2024 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on it

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): April 30, 2024

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On April 30, 2024, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended March 31, 2024. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated April 30, 2024 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:April 30, 2024By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): February 27, 2024

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On February 27, 2024, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the year ended December 31, 2023. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated February 27, 2024 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:February 27, 2024By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): October 26, 2023

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On October 26, 2023, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended September 30, 2023. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated October 26, 2023 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:October 26, 2023By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): July 27, 2023

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code) (617) 375-7500 (Registrant's telephone number, including area code) Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 4.125% Senior Notes due 2027AMT 27FNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 4.625% Senior Notes due 2031AMT 31BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On July 27, 2023, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended June 30, 2023. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated July 27, 2023 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:July 27, 2023By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20230426AMERICAN TOWER CORP /MA/0001053507false00010535072023-04-262023-04-260001053507exch:XNYSus-gaap:CommonStockMember2023-04-262023-04-260001053507exch:XNYSamt:A1375SeniorNotesDue2025Member2023-04-262023-04-260001053507amt:A1950SeniorNotesDue2026Memberexch:XNYS2023-04-262023-04-260001053507exch:XNYSamt:A0450SeniorNotesDue2027Member2023-04-262023-04-260001053507exch:XNYSamt:A0400SeniorNotesDue2027Member2023-04-262023-04-260001053507amt:A0500SeniorNotesDue2028Memberexch:XNYS2023-04-262023-04-260001053507exch:XNYSamt:A0875SeniorNotesDue2029Member2023-04-262023-04-260001053507amt:A0950SeniorNotesDue2030Memberexch:XNYS2023-04-262023-04-260001053507amt:A1000SeniorNotesDue2032Memberexch:XNYS2023-04-262023-04-260001053507amt:A1250SeniorNotesDue2033Memberexch:XNYS2023-04-262023-04-26

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): April 26, 2023

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On April 26, 2023, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended March 31, 2023. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated April 26, 2023 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:April 26, 2023By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20230223AMERICAN TOWER CORP /MA/0001053507false00010535072023-02-232023-02-230001053507us-gaap:CommonStockMemberexch:XNYS2023-02-232023-02-230001053507exch:XNYSamt:A1375SeniorNotesDue2025Member2023-02-232023-02-230001053507exch:XNYSamt:A1950SeniorNotesDue2026Member2023-02-232023-02-230001053507exch:XNYSamt:A0450SeniorNotesDue2027Member2023-02-232023-02-230001053507amt:A0400SeniorNotesDue2027Memberexch:XNYS2023-02-232023-02-230001053507exch:XNYSamt:A0500SeniorNotesDue2028Member2023-02-232023-02-230001053507exch:XNYSamt:A0875SeniorNotesDue2029Member2023-02-232023-02-230001053507exch:XNYSamt:A0950SeniorNotesDue2030Member2023-02-232023-02-230001053507exch:XNYSamt:A1000SeniorNotesDue2032Member2023-02-232023-02-230001053507exch:XNYSamt:A1250SeniorNotesDue2033Member2023-02-232023-02-23

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): February 23, 2023

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On February 23, 2023, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the year ended December 31, 2022. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated February 23, 2023 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:February 23, 2023By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20221027AMERICAN TOWER CORP /MA/0001053507false00010535072022-10-272022-10-270001053507exch:XNYSus-gaap:CommonStockMember2022-10-272022-10-270001053507amt:A1375SeniorNotesDue2025Memberexch:XNYS2022-10-272022-10-270001053507exch:XNYSamt:A1950SeniorNotesDue2026Member2022-10-272022-10-270001053507amt:A0450SeniorNotesDue2027Memberexch:XNYS2022-10-272022-10-270001053507exch:XNYSamt:A0400SeniorNotesDue2027Member2022-10-272022-10-270001053507exch:XNYSamt:A0500SeniorNotesDue2028Member2022-10-272022-10-270001053507exch:XNYSamt:A0875SeniorNotesDue2029Member2022-10-272022-10-270001053507exch:XNYSamt:A0950SeniorNotesDue2030Member2022-10-272022-10-270001053507exch:XNYSamt:A1000SeniorNotesDue2032Member2022-10-272022-10-270001053507amt:A1250SeniorNotesDue2033Memberexch:XNYS2022-10-272022-10-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): October 27, 2022

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On October 27, 2022, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended September 30, 2022. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated October 27, 2022 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:October 27, 2022By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20220728AMERICAN TOWER CORP /MA/0001053507false00010535072022-07-282022-07-280001053507us-gaap:CommonStockMemberexch:XNYS2022-07-282022-07-280001053507exch:XNYSamt:A1375SeniorNotesDue2025Member2022-07-282022-07-280001053507exch:XNYSamt:A1950SeniorNotesDue2026Member2022-07-282022-07-280001053507exch:XNYSamt:A0450SeniorNotesDue2027Member2022-07-282022-07-280001053507exch:XNYSamt:A0400SeniorNotesDue2027Member2022-07-282022-07-280001053507exch:XNYSamt:A0500SeniorNotesDue2028Member2022-07-282022-07-280001053507exch:XNYSamt:A0875SeniorNotesDue2029Member2022-07-282022-07-280001053507exch:XNYSamt:A0950SeniorNotesDue2030Member2022-07-282022-07-280001053507exch:XNYSamt:A1000SeniorNotesDue2032Member2022-07-282022-07-280001053507exch:XNYSamt:A1250SeniorNotesDue2033Member2022-07-282022-07-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): July 28, 2022

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On July 28, 2022, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended June 30, 2022. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated July 28, 2022 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:July 28, 2022By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20220427AMERICAN TOWER CORP /MA/0001053507false00010535072022-04-272022-04-270001053507us-gaap:CommonStockMemberexch:XNYS2022-04-272022-04-270001053507amt:A1375SeniorNotesDue2025Memberexch:XNYS2022-04-272022-04-270001053507amt:A1950SeniorNotesDue2026Memberexch:XNYS2022-04-272022-04-270001053507exch:XNYSamt:A0450SeniorNotesDue2027Member2022-04-272022-04-270001053507amt:A0400SeniorNotesDue2027Memberexch:XNYS2022-04-272022-04-270001053507exch:XNYSamt:A0500SeniorNotesDue2028Member2022-04-272022-04-270001053507amt:A0875SeniorNotesDue2029Memberexch:XNYS2022-04-272022-04-270001053507amt:A0950SeniorNotesDue2030Memberexch:XNYS2022-04-272022-04-270001053507amt:A1000SeniorNotesDue2032Memberexch:XNYS2022-04-272022-04-270001053507amt:A1250SeniorNotesDue2033Memberexch:XNYS2022-04-272022-04-27

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): April 27, 2022

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On April 27, 2022, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended March 31, 2022. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated April 27, 2022 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:April 27, 2022By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): February 24, 2022

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On February 24, 2022, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the year ended December 31, 2021. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated February 24, 2022 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:February 24, 2022By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

amt-20211028AMERICAN TOWER CORP /MA/0001053507false00010535072021-10-282021-10-280001053507us-gaap:CommonStockMemberexch:XNYS2021-10-282021-10-280001053507amt:A1375SeniorNotesDue2025Memberexch:XNYS2021-10-282021-10-280001053507amt:A1950SeniorNotesDue2026Memberexch:XNYS2021-10-282021-10-280001053507amt:A0450SeniorNotesDue2027Memberexch:XNYS2021-10-282021-10-280001053507exch:XNYSamt:A0400SeniorNotesDue2027Member2021-10-282021-10-280001053507exch:XNYSamt:A0500SeniorNotesDue2028Member2021-10-282021-10-280001053507amt:A0875SeniorNotesDue2029Memberexch:XNYS2021-10-282021-10-280001053507amt:A0950SeniorNotesDue2030Memberexch:XNYS2021-10-282021-10-280001053507exch:XNYSamt:A1000SeniorNotesDue2032Member2021-10-282021-10-280001053507exch:XNYSamt:A1250SeniorNotesDue2033Member2021-10-282021-10-28

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): October 28, 2021

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.400% Senior Notes due 2027AMT 27DNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 0.950% Senior Notes due 2030AMT 30CNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On October 28, 2021, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended September 30, 2021. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated October 28, 2021 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:October 28, 2021By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): July 29, 2021

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.450% Senior Notes due 2027AMT 27CNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 0.875% Senior Notes due 2029AMT 29BNew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange 1.250% Senior Notes due 2033AMT 33New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition.

On July 29, 2021, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended June 30, 2021. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated July 29, 2021 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:July 29, 2021By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON D.C. 20549

FORM 8-K

CURRENT REPORT PURSUANT

TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of Earliest Event Reported): April 29, 2021

AMERICAN TOWER CORPORATION

(Exact Name of Registrant as Specified in Charter)

Delaware 001-14195 65-0723837

(State or Other Jurisdiction of Incorporation) (Commission File Number) (I.R.S. Employer Identification No.)

116 Huntington Avenue Boston, Massachusetts 02116 (Address of Principal Executive Offices) (Zip Code)

(617) 375-7500 (Registrant's telephone number, including area code)

Not Applicable (Former name or former address, if changed since last report.) Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below): ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act:

Title of each classTrading Symbol(s)Name of each exchange on which registered Common Stock, $0.01 par value AMTNew York Stock Exchange 1.375% Senior Notes due 2025AMT 25ANew York Stock Exchange 1.950% Senior Notes due 2026AMT 26BNew York Stock Exchange 0.500% Senior Notes due 2028AMT 28ANew York Stock Exchange 1.000% Senior Notes due 2032AMT 32New York Stock Exchange

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Item 2.02    Results of Operations and Financial Condition. On April 29, 2021, American Tower Corporation (the “Company”) issued a press release (the “Press Release”) announcing financial results for the quarter ended March 31, 2021. A copy of the Press Release is furnished herewith as Exhibit 99.1.

Exhibit 99.1 is furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall such exhibit be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such a filing.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

Exhibit No. Description

99.1 Press Release, dated April 29, 2021 (Furnished herewith).

104Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

AMERICAN TOWER CORPORATION

(Registrant)

Date:April 29, 2021By:/s/ Rodney M. Smith Rodney M. Smith Executive Vice President, Chief Financial Officer and Treasurer