TMUS T Mobile US Inc

Exhibit 99.1

T-Mobile US, Inc. and T-Mobile USA, Inc. Announce Preliminary Results of Exchange Offers and Consent Solicitations for Certain of United States Cellular Corporation’s Outstanding Debt Securities

BELLEVUE, Wash., June 16, 2025—(BUSINESS WIRE)—T-Mobile US, Inc. (NASDAQ: TMUS) (the “Company”) today announced, together with T-Mobile USA, Inc., its wholly-owned subsidiary (“T-Mobile USA”), the preliminary results of its previously announced offers to exchange (the “Exchange Offers”) any and all of certain outstanding senior notes of United States Cellular Corporation (“USCC”). The Exchange Offers were launched pursuant to the Securities Purchase Agreement announced on May 28, 2024, under which the Company has agreed to purchase certain assets from USCC.

Today’s preliminary results concern the Company’s offers to exchange:

(i) USCC’s 6.700% Senior Notes due 2033 (the “Old USCC 2033 Notes”) for new 6.700% Senior Notes due 2033 to be issued by T-Mobile USA (the “New 2033 Notes”);

(ii) USCC’s 6.250% Senior Notes due 2069 (the “Old USCC 2069 Notes”) for new 6.250% Senior Notes due 2069 to be issued by T-Mobile USA (the “New 2069 Notes”);

(iii) USCC’s 5.500% Senior Notes due 2070 (March) (the “Old USCC March 2070 Notes”) for new 5.500% Senior Notes due March 2070 to be issued by T-Mobile USA (the “New March 2070 Notes”); and

(iv) USCC’s 5.500% Senior Notes due 2070 (June) (the “Old USCC June 2070 Notes” and, together with the Old USCC 2033 Notes, the Old USCC 2069 Notes and the Old USCC March 2070 Notes, the “Old USCC Notes”) for new 5.500% Senior Notes due June 2070 to be issued by T-Mobile USA (the “New June 2070 Notes” and, collectively with the New 2033 Notes, the New 2069 Notes and New March 2070 Notes, the “New T-Mobile Notes”);

in each case upon the terms and subject to the conditions set forth in the Prospectus, as defined below. In connection with the Exchange Offers, the Company and T-Mobile USA are also soliciting consents to amend the applicable indentures governing each series of the Old USCC Notes (the “Consent Solicitations”) to modify or eliminate certain notice requirements and restrictive covenants in the indentures governing the Old USCC Notes (the “Proposed Amendments”).

As of 5:00 p.m., New York City time, on June 13, 2025, which was the early participation date (the “Early Participation Date”) for the Exchange Offers and the Consent Solicitations, the principal amounts of the Old USCC Notes validly tendered and not validly withdrawn, as advised by D.F. King & Co., Inc., the exchange agent for the Exchange Offers, are set forth in the table below:

As of the Early Participation Date, the Company and T-Mobile USA have received valid consents to the Proposed Amendments from the holders of at least a majority of the outstanding aggregate principal amount of each series of the Old USCC Notes. Accordingly, the Proposed Amendments will become operative on the date on which the Acquisition (as defined in the Prospectus) closes, provided that if the Settlement Date (as defined in the Prospectus) has not occurred within five business days following the date on which the Acquisition closes, the Proposed Amendments previously effected shall be deemed null and void as if they had not occurred. The closing of the Acquisition is expected to occur by mid-2025, subject to the receipt of regulatory approvals and the satisfaction of customary closing conditions.

Holders of Old USCC 2033 Notes who validly tender such notes after the Early Participation Date but prior to the Expiration Date (as defined in the Prospectus), with such notes not validly withdrawn, will not be eligible to receive $30 principal amount of the New 2033 Notes (the “Old USCC 2033 Notes Early Participation Premium”) or a cash payment of $1.00 (the “Old USCC 2033 Notes Early Consent Fee”), and will only be eligible to receive $970 principal amount of the New 2033 Notes (the “Old USCC 2033 Notes Exchange Consideration”).

Holders of Old USCC 2069 Notes, Old USCC March 2070 Notes or Old USCC June 2070 Notes who validly tender such notes after the Early Participation Date but prior to the Expiration Date, with such notes not validly withdrawn, will not be eligible to receive $0.75 principal amount of the New 2069 Notes, the New March 2070 Notes or the New June 2070 Notes, respectively (the “Old USCC 2069 and Old USCC 2070 Notes Early Participation Premium”) or a cash payment of $0.025 (the “Old USCC 2069 and Old USCC 2070 Notes Early Consent Fee”), and will only be eligible to receive $24.25 principal amount of the New 2069 Notes, New March 2070 Notes and New June 2070 Notes, respectively (the “Old USCC 2069 and Old USCC 2070 Notes Exchange Consideration”).

As an update to the disclosure in the Prospectus, T-Mobile USA has applied to list the New 2069 Notes, New March 2070 Notes and New June 2070 Notes on Nasdaq’s Global Select Market and such notes are expected to trade on Nasdaq’s Global Select Market (and not Nasdaq’s U.S. Bond Exchange) on or promptly following the original issue date of such notes.

Withdrawal rights in connection with the Exchange Offers and Consent Solicitations expired at 5:00 p.m., New York City time, on June 13, 2025, which was the withdrawal deadline for the Exchange Offers and Consent Solicitations. Consents and tendered Old USCC 2033 Notes, Old USCC 2069 Notes, Old USCC March 2070 Notes and Old USCC June 2070 Notes, whether submitted prior or subsequent to such time, may not be validly revoked or withdrawn.

A Registration Statement on Form S-4 (the “Registration Statement”) and related prospectus and consent solicitation statement (as amended or supplemented from time to time, the “Prospectus”) relating to the issuance of the New T-Mobile Notes have been filed with the Securities and Exchange Commission (the “SEC”). If and when issued, the New T-Mobile Notes will be registered under the Securities Act of 1933, as amended.

Copies of the Prospectus pursuant to which the Exchange Offers and Consent Solicitations are being made may be obtained from D.F. King & Co., Inc., the information agent and exchange agent for the Exchange Offers and Consent Solicitations. Requests for documentation and questions regarding procedures for tendering the Old USCC Notes can be directed to D.F. King & Co., Inc. at (888) 605-1958 (for information U.S. Toll-free) or (212) 269-5550 (information for banks and brokers). Questions regarding the terms and conditions of the Exchange Offers and Consent Solicitations should be directed to the dealer managers, Morgan Stanley & Co. LLC and Wells Fargo Securities, LLC, at Morgan Stanley & Co. LLC, 1585 Broadway, New York, New York 10036, Attention: Global Debt Advisory Group, Collect: (212) 761-1057, Toll Free: (800) 624-1808, Email: lmny@morganstanley.com and Wells Fargo Securities, LLC, 550 South Tryon Street, 5th Floor, Charlotte, North Carolina 28202, Collect: (704) 410-4235, Toll Free: (866) 309-6316, Email: liabilitymanagement@wellsfargo.com, Attention: Liability Management Group, respectively.

Important Information about the Exchange Offers

The Exchange Offers and Consent Solicitations are being made only by and pursuant to the terms and subject to the conditions set forth in the Prospectus, which forms a part of the Registration Statement, and the information in this press release is qualified by reference to such Prospectus and the Registration Statement.

This press release is for informational purposes only and is not an offer to buy or sell or the solicitation of an offer to sell with respect to any securities. The Company is not making an offer of New T-Mobile Notes in any jurisdiction where the Exchange Offers are not permitted, and this press release does not constitute an offer to participate in the Exchange Offers to any person in any jurisdiction where it is unlawful to make such an offer or solicitations.

Holders of the Old USCC Notes are urged to carefully read the Prospectus before making any decision with respect to the Exchange Offers and Consent Solicitations. None of the Company, T-Mobile USA, the dealer managers, the trustee with respect to any series of Old USCC Notes, the trustee with respect to any series of New T-Mobile Notes, the information agent and exchange agent for the Exchange Offers or any affiliate of any of them makes any recommendation as to whether holders of the Old USCC Notes should exchange their Old USCC Notes for New T-Mobile Notes in the Exchange Offers, and no one has been authorized by any of them to make such a recommendation.

Holders of the Old USCC Notes must make their own decision as to whether to tender Old USCC Notes and, if so, the principal amount of Old USCC Notes to tender.

About the Company

T-Mobile US, Inc. is America’s supercharged Un-carrier, delivering an advanced 4G LTE and transformative nationwide 5G network that will offer reliable connectivity for all. T-Mobile’s customers benefit from its unmatched combination of value and quality, unwavering obsession with offering them the best possible service experience and undisputable drive for disruption that creates competition and innovation in wireless and beyond. Based in Bellevue, Wash., T-Mobile provides services through its subsidiaries and operates its flagship brands, T-Mobile, Metro by T-Mobile and Mint Mobile. For more information please visit: https://www.t-mobile.com.

Forward-Looking Statements

This press release contains forward-looking statements that are based on the Company’s management’s current expectations. Such statements include, without limitation, statements about the Exchange Offers and Consent Solicitations and the planned issuance of the New T-Mobile Notes. Such forward-looking statements are subject to certain risks, uncertainties and assumptions, including, without limitation, prevailing market conditions and other factors. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those expected. More information about potential risk factors that could affect the Company and its results is included in the Company’s filings with the SEC, which are available at http://www.sec.gov.

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