Exhibit 5.1

February 9, 2023

T-Mobile US, Inc.
T-Mobile USA, Inc.
12920 SE 38th Street
Bellevue, WA 98006

Ladies and Gentlemen:

We have acted as counsel to T-Mobile USA, Inc., a Delaware corporation (the “Company”), T-Mobile US, Inc., a Delaware corporation and the direct parent of the Company (the “Parent Guarantor”), the subsidiaries of the Company listed on Schedule I hereto (together with the Parent Guarantor, the “DE Guarantors”) and the subsidiaries of the Company listed on Schedule II hereto (the “Non-DE Guarantors” and, collectively with the DE Guarantors and the Parent Guarantor, the “Guarantors”), in connection with the Registration Statement on Form S-3 (File No. 333-249079), initially filed with the Securities and Exchange Commission (the “Commission”) on September 28, 2020 under the Securities Act of 1933, as amended (the “Securities Act”) as amended by Post-Effective Amendment No. 1 thereto, filed on March 30, 2021, by Post-Effective Amendment No. 2 thereto, filed on September 12, 2022 and by Post-Effective Amendment No. 3 thereto, filed on February 6, 2023 (the “Registration Statement”), with respect to the issuance of $1,000,000,000 in aggregate principal amount of the Company’s 4.950% Senior Notes due 2028 (the “2028 Debt Securities”) and the guarantees by the Guarantors thereof (the “2028 Debt Securities Guarantees”), $1,250,000,000 in aggregate principal amount of the Company’s 5.050% Senior Notes due 2033 (the “2033 Debt Securities”) and the guarantees by the Guarantors thereof (the “2033 Debt Securities Guarantees”) and $750,000,000 in aggregate principal amount of the Company’s 5.650% Senior Notes due 2053 (the “2053 Debt Securities”, and together with the 2028 Debt Securities and the 2033 Debt Securities, the “Debt Securities”) and the guarantees by the Guarantors thereof (the “2053 Debt Securities Guarantees” and, together with the 2028 Debt Securities Guarantees and the 2033 Debt Securities Guarantees, the “Debt Securities Guarantees”). The Debt Securities and the Debt Securities Guarantees are being offered and sold in a public offering pursuant to an underwriting agreement dated February 6, 2023, by and among the Company, the Guarantors and Deutsche Bank Securities Inc., Morgan Stanley & Co. LLC, RBC Capital Markets, LLC and Wells Fargo Securities, LLC, as representatives of the several underwriters (the “Underwriting Agreement”).

The Debt Securities and the Debt Securities Guarantees have been issued pursuant to an indenture, dated as of September 15, 2022 (the “Base Indenture”), among the Company, the Parent Guarantor and Deutsche Bank Trust Company Americas, as trustee (the “Trustee”), as supplemented by the Fourth Supplemental Indenture, dated as of February 9, 2023 (the “Fourth Supplemental Indenture”), among the Company, the Guarantors and the Trustee, with respect to the 2028 Debt Securities and the 2028 Debt Securities Guarantees, as further supplemented by the Fifth Supplemental Indenture, dated as of February 9, 2023 (the “Fifth Supplemental Indenture”), among the Company, the Guarantors and the Trustee, with respect to the 2033 Debt Securities and the 2033 Debt Securities Guarantees and as further supplemented by the Second Supplemental Indenture, dated as of September 15, 2022 (the “Second Supplemental Indenture”) and the Sixth Supplemental Indenture, dated as of February 9, 2023 (the “Sixth Supplemental Indenture”), in each case, among the Company, the Guarantors and the Trustee, with respect to the 2053 Debt Securities and the 2053 Debt Securities Guarantees (the Base Indenture, as supplemented by the Second Supplemental Indenture, the Fourth Supplemental Indenture, the Fifth Supplemental Indenture and the Sixth Supplemental Indenture, the “Indenture”).

In connection with this opinion, we have (i) investigated such questions of law, (ii) examined originals or certified, conformed, electronic or reproduction copies of such agreements, instruments, documents and records of the Company and the Guarantors, such certificates of public officials and such other documents and (iii) received such information from officers and representatives of the Company, the Guarantors and others, in each case as we have deemed necessary or appropriate for the purposes of this opinion. We have examined, among other documents, the following:

(a) the Underwriting Agreement;

(b) the Base Indenture;

(c) the Second Supplemental Indenture;

(d) the Fourth Supplemental Indenture;

(e) the Fifth Supplemental Indenture;

(f) the Sixth Supplemental Indenture; and

(g) the Debt Securities.

The documents referred to in items (a) through (g) above, inclusive, are referred to herein collectively as the “Documents.”

In all such examinations, we have assumed the legal capacity of all natural persons, the genuineness of all signatures, the authenticity of original and certified documents and the conformity to original or certified documents of all copies submitted to us as certified, conformed, electronic or reproduction copies. As to various questions of fact relevant to the opinion expressed herein, we have relied upon, and assume the accuracy of, the statements, representations and warranties contained in the Documents, certificates and oral or written statements and other information of or from public officials, officers or other appropriate representatives of the Company, the Guarantors and others and assume compliance on the part of all parties to the Documents with their respective covenants and agreements contained therein.

With your permission, all assumptions and statements of reliance herein have been made without any independent investigation or verification on our part and we express no opinion with respect to the subject matter or accuracy of such assumptions or items relied upon.

To the extent it may be relevant to the opinion expressed herein, we have assumed that (i) all of the parties to the Documents (other than the Company and the DE Guarantors) are validly existing and in good standing under the laws of their respective jurisdictions of organization; (ii) the parties to the Documents (other than the Company and the DE Guarantors) have the power and authority to (a) execute and deliver the Documents, (b) perform their obligations thereunder and (c) consummate the transactions contemplated thereby; (iii) each of the Documents has been duly authorized, executed and delivered by each of the parties thereto (other than the Company and the DE Guarantors); (iv) each of the Documents constitutes a valid and binding obligation of all of the parties thereto (other than as expressly addressed in the opinion below as to the Company and the Guarantors), enforceable against such parties in accordance with their respective terms and (v) all of the parties to the Documents will comply with all of their obligations under the Documents and all laws applicable thereto, (vi) the Debt Securities have been duly authenticated and delivered by the Trustee against payment therefor in accordance with the Documents and (vii) the Debt Securities conform to the specimens thereof examined by us.

Based upon the foregoing, and subject to the limitations, qualifications and assumptions set forth herein, we are of the opinion that the Debt Securities constitute valid and binding obligations of the Company enforceable against the Company in accordance with their terms and the Debt Securities Guarantees constitute valid and binding obligations of the Guarantors enforceable against the Guarantors in accordance with their terms.

The opinion set forth above is subject to the following qualifications:

The opinion expressed herein is limited to the laws of the State of New York and, to the extent relevant, the General Corporation Law of the State of Delaware, the Limited Liability Company Act of the State of Delaware and the Revised Uniform Limited Partnership Act of the State of Delaware, each as currently in effect, and no opinion is expressed with respect to any other laws or any effect that such other laws may have on the opinion expressed herein. The opinion expressed herein is limited to the matters stated herein, and no opinion is implied or may be inferred beyond the matters expressly stated herein. This letter is given only as of the time of its delivery, and we undertake no responsibility to update or supplement this letter after its delivery.

We hereby consent to the filing of this opinion as an exhibit to the Current Report on Form 8-K filed by the Company on the date hereof, which will be incorporated by reference in the Registration Statement and to the references to this firm under the caption “Legal Matters” in the prospectus supplements related to the Debt Securities and the Debt Securities Guarantees. In giving this consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Securities and Exchange Commission.

Schedule I

Subsidiary DE Guarantors

Schedule II

Subsidiary Non-DE Guarantors

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