Compensation Term Sheet, dated as of March 18, 2025, by and between T-Mobile US, Inc. and Michael J. Katz

This Compensation Term Sheet (the “Term Sheet”) between Michael J. Katz (“you”) and T-Mobile US, Inc. (the “Company”), effective as of March 18, 2025 (the “Effective Date”), confirms our understanding and agreement about your role and certain compensation opportunities with the Company following the Effective Date.

Please indicate your acceptance of, and agreement to, the terms and conditions outlined above by signing and dating this Term Sheet below.

                                                

                        

                                             

AGREED and ACCEPTED as of the date below:

1.“Cause” shall be defined as any one of the following: (i) your gross neglect or willful material breach of your principal employment responsibilities or duties, (ii) a final judicial adjudication that you are guilty of any felony (other than a law, rule or regulation relating to a traffic violation or other similar offense that has no material, adverse effect on the Company, Deutsche Telekom AG or their respective affiliates), (iii) your breach of the Restrictive Covenant Agreement or any other written non-competition, non-solicitation or confidentiality covenant between you and the Company or any affiliate of the Company (other than a de minimis breach), (iv) fraudulent conduct in the course of your employment with the Company as determined by a court of competent jurisdiction, (v) your unlawful discrimination, harassment, or retaliation, assault or other violent act toward any employee or third party, or other act or omission, in each case that in the reasonable and good faith view of the Board constitutes a material breach of the Company’s written policies or Code of Conduct, or (vi) your material breach of any other obligation to the Company or any of its affiliates which, if reasonably curable, continues uncured for a period of thirty (30) days after notice thereof by the Company or any of its affiliates (and which is demonstrably injurious to the Company or an affiliate thereof). Notwithstanding the foregoing, no cure period shall be required under the foregoing clause (vi) if the breach is a recurrence of conduct that was the subject of a prior notice under such clause (vi) for which a thirty (30)-day cure period was given. For purposes of the foregoing clause (vi), the term “obligation” refers to Company policies and directives and is not intended to refer to performance expectations such as goals set forth in bonus plans or performance evaluations.

2.“Good Reason” shall mean the occurrence of any of the following without your consent, provided that (a) you notify the Company within not more than ninety (90) days after its initial occurrence, (b) the Company does not cure such occurrence within thirty (30) days after receipt of such notice and (c) your employment with the Company terminates within sixty (60) days after the end of the Company’s cure period: (i) a material reduction in your Base Salary, annual Target STI award opportunity or annual Target LTI opportunity, except for across-the-board salary reductions based on the Company’s and subsidiaries’ financial performance similarly affecting all or substantially all management employees of the Company and its affiliates; (ii) the relocation of the office at which you are principally employed to a location more than fifty (50) miles from the location of such office, or you being required to be based anywhere other than such office, except for required travel on business; or (iii) with respect to any calendar year commencing during the Term (commencing with calendar year 2026 and measured as of January 1st of the applicable calendar year), your Base Salary and/or Target LTI opportunity for such calendar year is not equal to (or greater than) the 50th percentile of the then-current base salary and/or target long-term incentive opportunity (as applicable) for the most highly compensated executive officer role (excluding Chief Executive Officers, Chief Financial Officers and, if applicable, Executive Chairs) in the Company’s peer group utilized by the Committee for executive compensation decisions (as determined by the Committee) for such calendar year.

This Separation Agreement (“Agreement”) is entered into by Michael J. Katz (“Employee”) and T-Mobile US, Inc. (“Employer”).

1.SEPARATION DATE. Employee’s last date of employment with Employer is  [ l ] (the “Separation Date”), after which date Employee will claim no further right to employment.

2.EARNED PAYMENTS AND BENEFITS. Employee acknowledges and agrees he has been provided all compensation and benefits to which Employee is or may be entitled by virtue of Employee’s employment with Employer, except as otherwise provided herein and except to the extent that Employee may still be owed salary earned during the last pay period before the Separation Date and accrued unused paid time off. If Employee is enrolled in Employer’s group medical, dental, or vision plan at the time of separation from employment Employee will remain eligible for such coverage through the end of the month in which Employee remains employed with Employer. Eligibility for Employer provided health or dependent care flexible spending account, life and disability, and all other benefit plans cease on the Separation Date. After the Separation Date, Employee may exercise at Employee’s sole expense whatever rights Employee may have to continuation of medical, dental, or vision benefits under Employer’s group plan under COBRA, and any conversion rights under any life or other applicable insurance program. Any amounts Employee may have as a vested account balance under Employer’s 401(k) plan will be handled in accordance with the terms and conditions of such plan. Except as stated in this Agreement, or as required by law, any rights that Employee may have to payments and benefits by virtue of employment with Employer cease on the Separation Date.

3.ADDITIONAL PAYMENT. In consideration of Employee’s waiver and release and covenants under this Agreement, and provided that the period under Section 10 during which Employee is entitled to revoke the release has expired, Employer will provide Employee with the payments and benefits set forth in the section entitled [“Severance”]/[“Death; Disability”] in Compensation Term Sheet between Employee and Employer, effective as of March 18, 2025 (the “Term Sheet”) from which usual and customary withholdings and deductions other than 401(k) contributions will be subtracted (the aggregate amounts due under such clauses is referred to herein as the “Separation Payments and Benefits”). The Separation Payments and Benefits will be paid at such time(s) as provided in the Term Sheet, provided that Employee has executed and not revoked this Agreement. Employee acknowledges that (a) Employer is not obligated to provide Employee with the Separation Payments and Benefits provided in this Section 3, except under this Agreement, (b) Employer’s obligations set forth in this Agreement provide adequate consideration for Employee’s covenants, waiver, and release in this Agreement, and (c) Employee’s entitlement to earn the Separation Payments and Benefits is conditioned on Employee’s full compliance with this Agreement (including Sections 5, 6, 7, 8, and 14) and any other obligations under other agreements between Employee and the Employer, including without limitation the Restrictive Covenant Agreement (as defined in the Term Sheet) annexed as Attachment E to the Term Sheet. Employee acknowledges and agrees that Employee will be ineligible for rehire at Employer in consideration of receiving payments under this Agreement unless prohibited by law. For purposes of this Agreement, “Affiliate” means any entity currently existing or subsequently organized or formed that directly or indirectly controls, is controlled by, or is under common control with Employer or the entities who

control Employer, whether through the ownership of voting securities, by contract or otherwise, including without limitation Deutsche Telekom AG.

4.WAIVER AND RELEASE. For the purposes of this Agreement, the term “Released Parties” means Employer, its parent(s) (including Deutsche Telekom AG), subsidiaries, and Affiliates, and all of its and their respective companies and its and their present, former, and future successors and assigns, and all of its and their present, former, and future officers, directors, stockholders, employees, agents, trustees, partners, members, and attorneys, in their individual and representative capacities. On behalf of Employee and Employee’s marital community, heirs, executors, administrators, and assigns, Employee expressly waives, releases, and discharges any and all claims, whether known or unknown, against any or all of the Released Parties, to the extent that any acts or omissions related to or connected with such claims occurred or could be alleged to have occurred before the execution of this Agreement (“Released Claims”). Released Claims include claims (including claims to attorneys’ fees), damages, losses, causes of action, and disputes of any kind whatsoever, including without limitation all claims for wages, compensation, employee benefits, and damages arising out of any: contracts, express or implied, including without limitation the Term Sheet; any incentive compensation, bonus, or retention or equity plans; tort; discrimination; wrongful termination; any federal, state, local, or other governmental statute or ordinance, including without limitation Title VII of the Civil Rights Act of 1964, as amended; the Age Discrimination in Employment Act, as amended (“ADEA”); the Employee Retirement Income Security Act of 1974, as amended (“ERISA”); the Family and Medical Leave Act (“FMLA”); the Americans with Disabilities Act; the Washington Paid Sick Leave Act; RCW 49.46.005 to RCW 49.46.920 and Wash. Admin. Code 296-128-600to 296-128-760; the Washington Family Care Act, RCW 49.12.265 and Wash. Admin. Code 296-130-010 to 296-130-100; the Washington Domestic Violence Leave Act, RCW 49.76.010 to RCW 49.76.900; the Washington Military Family Leave Act; RCW 49.77.010 to RCW 49.77.900; the Washington law concerning leave for certain emergency services personnel, RCW 49.12.460; the Washington Minimum Wage Act, RCW 49.46.005 to 49.46.920; the Washington Industrial Welfare Act, RCW 49.12.005 to 49.12.903; the Washington Law Against Discrimination, RCW 49.60.010 to 49.60.510; the Washington Wage Payment Act and the Wage Rebate Act, RCW 49.48.010 to 49.48.900 and 49.52.010 to 49.52.090; and any other employment and wage and hour laws of the state of Washington and any other applicable state; and any other legal limitation on the employment relationship. Notwithstanding the foregoing, “Released Claims” do not include claims for breach or enforcement of this Agreement, claims that arise after the execution of this Agreement, claims to vested benefits under ERISA, unemployment compensation claims, claims for indemnification and rights to coverage under Employer’s director and officer policies to the extent provided to you as of the Separation Date, claims to the Separation Payments and Benefits, or any other claims that may not be released under this Agreement in accordance with applicable law. Employee agrees to cooperate fully with Employer and its agents in seeking any governmental or judicial approval of the terms of this Agreement in order to ensure that it is fully enforceable as written, to the extent such approval becomes necessary. Employee further represents and warrants that Employee has no present or past claim against Employer alleging any violation of the FMLA and/or the FLSA.

Employee expressly understands and acknowledges that it is possible that unknown claims (including claims for attorneys’ fees), damages, losses, causes of action, or disputes exist or may have been underestimated in amount or severity. Employee expressly accepts and assumes the risk of such unknown or underestimated claims, damages, losses, causes of action, and disputes and acknowledges and agrees that the benefits to be provided to Employee pursuant to this Agreement fully compensate Employee for such risks.

5.COVENANT NOT TO SUE. Employee represents and warrants that Employee has not filed any litigation based on any Released Claims. Employee covenants and promises never to file, press, or join in any lawsuit based on any Released Claim and agrees that any such claim, if filed by Employee, will be dismissed, except that this covenant and promise does not apply to any claim of Employee challenging the validity of this Agreement in connection with claims arising under the ADEA and/or the Older Workers’ Benefit Protection Act of 1990 (“OWBPA”). Employee represents and warrants: (a) at the time of execution of this Agreement, Employee has no knowledge of any Released Claims that Employee may have had to assert against Employer except for those that Employee reported in writing to Employers Chief People Officer before Employee’s execution of this Agreement; (b) Employee is the sole owner of any and all Released Claims that Employee may have; and (c) Employee has not assigned or otherwise transferred Employee’s right or interest in any Released Claim.

6.EMPLOYER PROPERTY. Employee represents and warrants that Employee has turned over to Employer all property of Employer and Deutsche Telekom AG, including without limitation all files, memoranda, keys, manuals, notebooks, hard drives, USB drives, CDs, DVDs, equipment, data, records, and other documents, including electronically recorded documents and data that Employee received from Employer or Deutsche Telekom AG or their employees or that Employee generated in the course of employment with Employer or Deutsche Telekom AG. Employee further represents and warrants that Employee has disclosed to Employer all passwords, codes, or any other mechanism by which Employee has or had access to Employers computer systems or facilities. Employee promises not to access or attempt to access Employers or its Affiliates’ computer systems or software or facilities as of the Separation Date or thereafter, nor will Employee provide information to any other person or entity that will allow that party unauthorized access to Employers or its Affiliates’ computer systems or software or facilities.

7.CONFIDENTIALITY. Employee acknowledges and agrees that Employee has had obligations to protect, keep confidential, and not use other than for the best interests of Employer the confidential or proprietary information or intellectual property of Employer or its Affiliates or to transfer to Employer or its Affiliates any interest in intellectual property to Employer, whether contractual or otherwise, including under any restrictive covenants to which Employee has agreed, under common law and statutes, and otherwise (collectively, “IP Obligations”). Employee acknowledges and agrees that the IP Obligations will remain in full force and effect and that Employee will comply fully with such obligations. Employee represents and warrants that Employee has been in full compliance with the IP Obligations at all times before entry into this Agreement. In addition to and not in place of any IP Obligations Employee may have, Employee agrees not to use or disclose any confidential or proprietary information or trade secrets of Employer or any of its Affiliates. For the purposes of this Agreement, “confidential or proprietary information or trade secrets” means all data and information in whatever form, tangible or intangible, that is not generally known to the public and that relates to the business, technology, strategies, practices, products, marketing, sales, services, finances, or legal affairs of Employer or its Affiliates or any third party doing business with or providing information to Employer or its Affiliates. Employee agrees and acknowledges that the terms and conditions of this Agreement are confidential and will not be disclosed to any third party, except for Employee’s spouse, attorney, or financial advisor, who Employee covenants will comply with this provision. Employee will refrain from making disparaging statements about Employer or its Affiliates, or any of their personnel, products, or services. Nothing in this Section 7 is intended to restrict Employee’s compliance with law or the legal process. Further, notwithstanding the foregoing or anything herein to the contrary, Employee understands that (a) nothing contained herein will prohibit Employee from filing a charge with, reporting possible violations of federal law or regulation to, participating in any investigation by, or cooperating with any governmental agency or entity or making

other disclosures that are protected under the whistleblower provisions of applicable law or regulation; (b) nothing herein is intended to or will prevent Employee from communicating directly with, cooperating with, or providing information (including trade secrets) in confidence to, any federal, state or local government regulator (including, but not limited to, the U.S. Securities and Exchange Commission, the U.S. Commodity Futures Trading Commission, the U.S. Department of Justice or the U.S. National Labor Relations Board or any similar agency) for the purpose of reporting or investigating a suspected violation of law, or from providing such information to Employee’s attorney or in a sealed complaint or other document filed in a lawsuit or other governmental proceeding, or from exercising any rights the Employee may have, if any, under Section 7 of the U.S. National Labor Relations Act; and (c) pursuant to 18 USC Section 1833(b), (x) Employee will not be held criminally or civilly liable under any federal or state trade secret law for the disclosure of a trade secret that is made: (i) in confidence to a federal, state, or local government official, either directly or indirectly, or to an attorney, and solely for the purpose of reporting or investigating a suspected violation of law; or (ii) in a complaint or other document filed in a lawsuit or other proceeding, if such filing is made under seal, and (y) if the Employee files a lawsuit for retaliation by an employer for reporting a suspected violation of law, the Employee may disclose a trade secret to his attorney and use the trade secret information in the court proceeding, if the Employee (A) files any document containing the trade secret under seal, and (B) does not disclose the trade secret, except pursuant to court order.

8.INTELLECTUAL PROPERTY.

(a)In addition to Employee’s obligation under the IP Obligations, and subject to Sections 8(b) and 8(c) below, Employee hereby assigns all right, title, and interest in and to all Inventions to Employer, its successors, and assigns. “Inventions” means any and all inventions, software, discoveries, developments, concepts, ideas, know-how, trade secrets, prototypes, designs, methods, processes, and techniques, and improvements to any of the foregoing, which Employee conceived, authored, or otherwise generated and/or reduced to practice (alone or jointly with any of Employer’s employees or agents) in the course of Employee’s employment with Employer.

(b)NOTICE: The obligation to assign inventions under Section 8(a) will not apply to any inventions for which no equipment, supplies, facilities, or trade secret information of Employer were used and that were developed entirely on Employee’s own time, unless (i) the invention relates (A) directly to the business of Employer, or (B) to Employer’s actual or demonstrably anticipated research or development, or (ii) the invention results from any work performed by Employee for Employer.

(c)To the extent that Employee used or incorporated (or permitted others to use or incorporate) any of Employee’s proprietary know-how that was in existence before Employee’s employment with Employer (“Existing Employee Know-How”) in any services, technology, or products prepared or produced in connection with employment with Employer, Employee hereby grants to Employer a non-exclusive, irrevocable, perpetual, royalty-free, fully paid up, worldwide right and license under such Existing Employee Know-How (including any patent or other intellectual property rights therein) to further develop, make, use, sell, and import any and all services, technology, or products, and to sublicense any or all of the foregoing rights (including the right to grant further sublicenses), for so long as such Existing Employee Know-How is in existence and is licensable by Employee.

(d)To the extent any materials Employee created within the scope of employment may be considered “works made for hire” under United States copyright laws, they are hereby agreed to be works made for hire. To the extent any such works do not qualify as a “work made for hire” under applicable law, and to the extent they include material subject to copyright, mask work, trademark, trade secret, or

any other proprietary rights protection, and to the extent they are not Existing Employee Know How, Employee hereby irrevocably and exclusively assigns and agrees to assign to Employer, its successors, and assigns, all right, title, and interest in and to all such materials. To the extent any of Employee’s rights in the same, including any moral rights, are not subject to assignment hereunder, Employee hereby irrevocably and unconditionally waives all enforcement of such rights.

(e)Employee agrees to execute and deliver such instruments and take such other actions as may be required to carry out the assignments contemplated by this Section 8. If Employee fails to execute such instruments by reason of Employee’s mental or physical disability or any other reason, Employee hereby irrevocably appoints Employer and its officers and agents as Employee’s agent and attorney-in-fact to execute such instruments on Employee’s behalf.

9.REMEDIES. Employee acknowledges and agrees that breach of any of the covenants contained in Sections 5, 6, 7, 8, and 14 of this Agreement constitutes a material breach of this Agreement that may cause Employer or its Affiliates irreparable harm and will entitle the Employer and its Affiliates to all remedies provided by law, including injunctive relief.

10.CONSIDERATION AND REVOCATION PERIOD. Following delivery of this Agreement, Employee has 21 days to review and consider this Agreement, after which time the offer of this Agreement will expire and may no longer be accepted (provided that if the 21-day consideration period expires before the Separation Date, Employee cannot sign the Agreement until the Separation Date and it will not expire before the Separation Date). Employee may accept this Agreement before the expiration of the 21-day consideration period and if Employee does so, by Employee’s signature, Employee expressly acknowledges that Employee has knowingly and voluntarily chosen to sign this Agreement before the expiration of the 21-day consideration period. Employee has a period of seven calendar days after delivering the executed Agreement to Employer to revoke acceptance of the Agreement. To revoke, Employee must deliver a notice revoking Employee’s acceptance of this Agreement to the attention of the Vice President of Legal Affairs, T-Mobile US, Inc., 12920 SE 38th Street, Bellevue, WA 98006. This Agreement shall become effective on the eighth day after delivery of this executed Agreement by Employee to Employer, provided that Employee has not revoked acceptance or rescinded the Agreement.

11.ENTIRE AGREEMENT/AMENDMENT/SEVERABILITY. This Agreement constitutes the entire understanding between Employer and Employee as it relates to the subject matter of this Agreement and supersedes all other representations, statements, and understandings or agreements pertaining to such subject matter, except that this Agreement does not supersede any of Employee’s existing obligations (a) to Employer (including the IP Obligations or any Employee obligation to arbitrate disputes) or (b) under other agreements between Employee and Employer (including any and all restrictive covenants to which Employee may have agreed), all of which remain in full force and effect. The provisions of this Agreement are severable, and if any provision of it is found to be unlawful or unenforceable, it will be deemed narrowed to the extent required to make it lawful and enforceable. If such modification is not possible, such provision will be severed from the Agreement and the remaining provisions will remain fully valid and enforceable to the maximum extent consistent with applicable law, provided, however, that Section 4 may not be severed from the Agreement. Nothing in this Agreement reflects any admission of liability by Employer or Employee.

12.KNOWING AND VOLUNTARY AGREEMENT. Employee hereby warrants and represents that: (a) Employee has carefully read this Agreement and finds that it is written in a manner that Employee understands; (b) Employee knows the contents of this Agreement; (c) Employee is and has been advised to consult and has either discussed the Agreement and its effects

13.VENUE/CHOICE OF LAW. The exclusive venue of any litigation arising from this Agreement will be King County, Washington, except that the parties may seek injunctive relief in any court with jurisdiction. This Agreement will be governed by and interpreted under the laws of the state of Washington, excluding its choice of law rules.

14.COOPERATION. In return for the amounts paid hereunder, Employee agrees to cooperate in defense of Employer and its Affiliates in any legal action or claim in which Employee is named as a witness. Cooperation will include, upon request by Employer, preparing for, participating in and testifying at depositions, trials, mediations, arbitrations, or other hearings; providing information in written format such as declaration or affidavit; and providing general assistance to Employer, its Affiliates, and their attorneys.

It is intended that the payments and benefits under this Term Sheet comply with the provisions of Section 409A and the Treasury regulations relating thereto, or satisfy the requirements for an exemption from Section 409A, in each case to the extent applicable to this Agreement and, accordingly, to the maximum extent permitted, this Term Sheet shall be interpreted and be administered in a manner to be in compliance therewith. Notwithstanding anything contained herein to the contrary, to the extent required in order to avoid accelerated taxation and/or tax penalties under Section 409A, you shall not be considered to have terminated employment with the Company for purposes of this Term Sheet, and no payment otherwise due upon a termination of employment shall be due to you under this Term Sheet, until you would be considered to have incurred a “separation from service” from the Company within the meaning of Section 409A (a “Separation from Service”). Any payments described in this Term Sheet that qualify for the “short-term deferral” exception from Section 409A shall not be treated as deferred compensation as described in Treasury Regulation Section 1.409A-1(b)(4) and will be paid under such exception unless applicable law requires otherwise. For purposes of Section 409A (including, without limitation, for purposes of Treasury Regulation Section 1.409A-2(b)(2)(iii) and the application of the short-term deferral exception), each payment under this Term Sheet will be treated as a separate payment. Notwithstanding anything to the contrary in this Term Sheet (whether under this Term Sheet or otherwise), to the extent delayed commencement of any portion of the payments to be made to you upon your Separation from Service is required to avoid a prohibited payment under Section 409A(a)(2)(B)(i) of the Code, such portion of the payments shall be delayed and paid on the first business day after the earlier of (i) the date that is six (6) months following such Separation from Service or (ii) your death. Notwithstanding anything contained herein to the contrary, to the extent required in order to avoid accelerated taxation and/or tax penalties under Section 409A, amounts reimbursable to you under this Term Sheet shall be paid to you on or before the last day of the year following the year in which the expense was incurred and the amount of expenses eligible for reimbursement (and in-kind benefits provided to you) during any one year may not affect amounts reimbursable or provided in any subsequent year and may not be liquidated or exchanged for any other benefit. Notwithstanding anything in the Term Sheet to the contrary, in the event that the aggregate period during which you are (or your estate is) entitled to consider and/or revoke the Release spans two calendar years, then to the extent required by Section 409A, no payments under the Severance or Death; Disability paragraphs will be made prior to the beginning of the second such calendar year (and any such payments otherwise payable prior thereto (if any) will instead be paid on the first regularly scheduled Company payroll date occurring in the latter such calendar year or, if later, on the first regularly scheduled Company payroll date following the effectiveness of the Release).

In the event any payment, benefit or distribution of any type to or for the benefit of you, whether paid or payable, provided or to be provided, or distributed or distributable pursuant to the terms of this Term Sheet or otherwise, constitutes a “parachute payment” under Section 280G of the Code, the amount payable to you shall be either (a) paid in full, or (b) paid after reduction by the smallest amount as would result in no portion thereof being subject to the excise tax under Section 4999 of the Code, whichever of the foregoing amounts, taking into account the applicable federal, state and local income taxes and the excise tax under Section 4999 of the Code, results in the receipt by you, on an after-tax basis, of the greater net value, notwithstanding that all or some portion of such payment amount may be taxable under Section 4999 of the Code. Unless the Company and you otherwise agree in writing, all determinations required to be made under this paragraph, including the manner and amount of any reduction in your payments hereunder, and the assumptions to be utilized in arriving at such determinations, shall be made in writing in good faith by the accounting firm serving as the Company’s independent public accounting firm immediately prior to the event giving rise to such payment (the “Accounting Firm”); provided, however, that no such reduction or elimination shall apply to any non-qualified deferred compensation amounts (within the meaning of Section 409A of the Code) to the extent such reduction or elimination would accelerate or defer the timing of such payment in manner that does not comply with Section 409A of the Code. For purposes of making the calculations required by this paragraph, the Accounting Firm may make reasonable assumptions and approximations concerning the application of Sections 280G and 4999 of the Code. The Company and you shall furnish to the Accounting Firm such information and documents as the Accounting Firm may reasonably request to make a determination under this paragraph. The Accounting Firm shall provide its written report to the Committee and you, which shall include information regarding methodology. The Company shall bear all costs the Accounting Firm may reasonably incur in connection with any calculations contemplated by this paragraph. You and the Company shall cooperate in case of a potential Change in Control to consider alternatives to mitigate any Section 280G exposure, although the Company cannot guaranty any such alternatives will be available or approved by the Company and neither you nor the Company shall be obligated to enter into them.