# EDGAR Filing Document

**Accession Number:** 0001051512
**File Stem:** 0001051512-26-000057
**Filing Date:** 2026-6
**Character Count:** 47111
**Document Hash:** d824a0ba997429d214ee6ce41bcafe38
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001051512-26-000057.hdr.sgml**: 20260602

**ACCESSION NUMBER**: 0001051512-26-000057

**CONFORMED SUBMISSION TYPE**: 11-K

**PUBLIC DOCUMENT COUNT**: 32

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260602

**DATE AS OF CHANGE**: 20260602

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** TELEPHONE & DATA SYSTEMS INC /DE/
- **CENTRAL INDEX KEY:** 0001051512
- **STANDARD INDUSTRIAL CLASSIFICATION:** TELEPHONE COMMUNICATIONS (NO RADIO TELEPHONE) [4813]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 362669023
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 11-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-14157
- **FILM NUMBER:** 261056140

**BUSINESS ADDRESS:**
- **STREET 1:** 30 NORTH LASALLE STREET
- **STREET 2:** STE 4000
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60602
- **BUSINESS PHONE:** 3126301900

**MAIL ADDRESS:**
- **STREET 1:** 30 NORTH LASALLE STREET
- **STREET 2:** STE 4000
- **CITY:** CHICAGO
- **STATE:** IL
- **ZIP:** 60602

?xml version='1.0' encoding='ASCII'? tds-20251231

---

| | |
|:---|:---|
| **UNITED STATES** | **UNITED STATES** |
| **SECURITIES AND EXCHANGE COMMISSION** | **SECURITIES AND EXCHANGE COMMISSION** |
| **Washington, D.C. 20549** | **Washington, D.C. 20549** |
| **FORM 11-K** | **FORM 11-K** |
| (Mark one) |  |
| **[x]** | **ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|  | **ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|  | **For the fiscal year ended December 31, 2025** |
| **OR** | **OR** |
| **[ ]** | **TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|  | **TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934** |
|  | **For the transition period from ________________ to ________________** |
| **Commission File Number:** | **001-14157 (Telephone and Data Systems, Inc.)** |
|  | **001-09712 (Array Digital Infrastructure, Inc.)** |
| A. Full title of the plan and the address of the plan, if different from that of the issuer named below: | A. Full title of the plan and the address of the plan, if different from that of the issuer named below: |
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** |
| **30 North LaSalle Street** | **30 North LaSalle Street** |
| **Suite 4000** | **Suite 4000** |
| **Chicago, IL 60602** | **Chicago, IL 60602** |
| B. Name of issuers of the securities held pursuant to the plan and the addresses of the principal executive office: | B. Name of issuers of the securities held pursuant to the plan and the addresses of the principal executive office: |
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **30 North LaSalle Street** | **30 North LaSalle Street** |
| **Suite 4000** | **Suite 4000** |
| **Chicago, IL 60602** | **Chicago, IL 60602** |
| **Array Digital Infrastructure, Inc.** | **Array Digital Infrastructure, Inc.** |
| **500 West Madison Street, Suite 810** | **500 West Madison Street, Suite 810** |
| **Chicago, IL 60661** | **Chicago, IL 60661** |

---

------

---

| | | |
|:---|:---|:---|
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **Tax–Deferred Savings Plan** | **Tax–Deferred Savings Plan** | **Tax–Deferred Savings Plan** |
| Financial Report | Financial Report | Financial Report |
| December 31, 2025 | December 31, 2025 | December 31, 2025 |
| **Table of Contents** | **Table of Contents** |  |
| <u>[Report of Independent Registered Public Accounting Firm - BDO USA, P.C.](#i77f39d4b9ab146d998694527a60dead3_7)</u> | <u>[Report of Independent Registered Public Accounting Firm - BDO USA, P.C.](#i77f39d4b9ab146d998694527a60dead3_7)</u> | <u>[1](#i77f39d4b9ab146d998694527a60dead3_7)</u> |
| <u>[Financial Statements](#i77f39d4b9ab146d998694527a60dead3_10)</u> | <u>[Financial Statements](#i77f39d4b9ab146d998694527a60dead3_10)</u> |  |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statements of Net Assets Available for Benefits](#i77f39d4b9ab146d998694527a60dead3_10)</u> | &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statements of Net Assets Available for Benefits](#i77f39d4b9ab146d998694527a60dead3_10)</u> | <u>[2](#i77f39d4b9ab146d998694527a60dead3_10)</u> |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statement of Changes in Net Assets Available for Benefits](#i77f39d4b9ab146d998694527a60dead3_13)</u> | &nbsp;&nbsp;&nbsp;&nbsp;<u>[Statement of Changes in Net Assets Available for Benefits](#i77f39d4b9ab146d998694527a60dead3_13)</u> | <u>[3](#i77f39d4b9ab146d998694527a60dead3_13)</u> |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Notes to Financial Statements](#i77f39d4b9ab146d998694527a60dead3_16)</u> | &nbsp;&nbsp;&nbsp;&nbsp;<u>[Notes to Financial Statements](#i77f39d4b9ab146d998694527a60dead3_16)</u> | <u>[4](#i77f39d4b9ab146d998694527a60dead3_16)</u> |
| <u>[Supplemental Information](#i77f39d4b9ab146d998694527a60dead3_37)</u> | <u>[Supplemental Information](#i77f39d4b9ab146d998694527a60dead3_37)</u> |  |
| &nbsp;&nbsp;&nbsp;&nbsp;<u>[Schedule H, Line 4i - Schedule of Assets (Held at End of Year)](#i77f39d4b9ab146d998694527a60dead3_37)</u> | &nbsp;&nbsp;&nbsp;&nbsp;<u>[Schedule H, Line 4i - Schedule of Assets (Held at End of Year)](#i77f39d4b9ab146d998694527a60dead3_37)</u> | <u>[10](#i77f39d4b9ab146d998694527a60dead3_37)</u> |
| <u>[Exhibits](#i77f39d4b9ab146d998694527a60dead3_40)</u> | <u>[Exhibits](#i77f39d4b9ab146d998694527a60dead3_40)</u> | <u>[11](#i77f39d4b9ab146d998694527a60dead3_40)</u> |
| **No.** | **Description** | **Description** |
| 23 | <u>[Consent of Independent Registered Public Accounting Firm - BDO USA, P.C](tds202511-kexhibit23.htm)</u>. | <u>[Consent of Independent Registered Public Accounting Firm - BDO USA, P.C](tds202511-kexhibit23.htm)</u>. |

---

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

BDO USA, P.C.

**Report of Independent Registered Public Accounting Firm**

To the Investment Management Committee and Plan Participants of

Telephone and Data Systems, Inc. Tax-Deferred Savings Plan

Madison, Wisconsin

**Opinion on the Financial Statements**

We have audited the accompanying statements of net assets available for benefits of the Telephone and Data Systems, Inc. Tax-Deferred Savings Plan (the "Plan") as of December 31, 2025 and 2024, the related statement of changes in net assets available for benefits for the year ended December 31, 2025, and the related notes (collectively, the "financial statements"). In our opinion, the financial statements present fairly, in all material respects, the net assets available for benefits of the Plan as of December 31, 2025 and 2024, and the changes in net assets available for benefits for the year ended December 31, 2025, in conformity with accounting principles generally accepted in the United States of America.

**Basis for Opinion**

These financial statements are the responsibility of the Plan's management. Our responsibility is to express an opinion on the Plan's financial statements based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Plan in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement, whether due to error or fraud. The Plan is not required to have, nor were we engaged to perform, an audit of its internal control over financial reporting. As part of our audits we are required to obtain an understanding of internal control over financial reporting but not for the purpose of expressing an opinion on the effectiveness of the Plan's internal control over financial reporting. Accordingly, we express no such opinion.

Our audits included performing procedures to assess the risk of material misstatement of the financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by the Plan's management, as well as evaluating the overall presentation of the financial statements. We believe that our audits provide a reasonable basis for our opinion.

**Supplemental Information**

The supplemental information in the accompanying ERISA-required Supplemental Schedule H, Line 4i – Schedule of Assets (Held at End of Year) as of December 31, 2025 has been subjected to audit procedures performed in conjunction with the audit of the Plan's financial statements. The supplemental information is presented for the purpose of additional analysis and is not a required part of the financial statements but included supplemental information required by the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. The supplemental information is the responsibility of the Plan's management. Our audit procedures included determining whether the supplemental information reconciles to the financial statements or the underlying accounting and other records, as applicable, and performing procedures to test the completeness and accuracy of the information presented in the supplemental information. In forming our opinion on the supplemental information, we evaluated whether the supplemental information, including its form and content, is presented in conformity with the Department of Labor's Rules and Regulations for Reporting and Disclosure under the Employee Retirement Income Security Act of 1974. In our opinion, the supplemental information is fairly stated, in all material respects, in relation to the financial statements as a whole.

/s/ BDO USA, P.C.

We have served as the Plan's auditor since 2022.

Madison, Wisconsin

June 2, 2026

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

---

| | | |
|:---|:---|:---|
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** |
| **Statements of Net Assets Available for Benefits** | **Statements of Net Assets Available for Benefits** | **Statements of Net Assets Available for Benefits** |
| **December 31, 2025 and 2024** | **December 31, 2025 and 2024** | **December 31, 2025 and 2024** |
| (Dollars in thousands) | **2025** | 2024 |
| **Assets** |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Investments, at fair value | $**1579176** | $1762483 |
| **Receivables** |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Accrued income | **224** | 222 |
| &nbsp;&nbsp;&nbsp;&nbsp;Contributions receivable from participants and employer | **1915** | 3001 |
| &nbsp;&nbsp;&nbsp;&nbsp;Notes receivable from participants | **8209** | 14899 |
| &nbsp;&nbsp;&nbsp;&nbsp;Due from broker for securities sold | **114** | **—** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total receivables | **10462** | 18122 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**Total assets** | **1589638** | 1780605 |
| **Liabilities** |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Distributions in transit and other | **492** | 709 |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**Total liabilities** | **492** | 709 |
| **Net assets available for benefits** | $**1589146** | $1779896 |
| The accompanying notes are an integral part of these financial statements. | The accompanying notes are an integral part of these financial statements. | The accompanying notes are an integral part of these financial statements. |

---

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

---

| | |
|:---|:---|
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** |
| **Statement of Changes in Net Assets Available for Benefits** | **Statement of Changes in Net Assets Available for Benefits** |
| **Year Ended December 31, 2025** | **Year Ended December 31, 2025** |
| (Dollars in thousands) |  |
| **Additions to plan assets attributed to** |  |
| Investment income: |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Interest and dividends | $**14234** |
| &nbsp;&nbsp;&nbsp;&nbsp;Net appreciation in fair value of investments | **263018** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total investment income | **277252** |
| Interest income on notes receivable from participants | **973** |
| Contributions: |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Participant | **58658** |
| &nbsp;&nbsp;&nbsp;&nbsp;Participant rollover | **9556** |
| &nbsp;&nbsp;&nbsp;&nbsp;Employer | **21808** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total contributions | **90022** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total additions | **368247** |
| **Deductions from plan assets attributed to** |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Benefits paid to participants | **557151** |
| &nbsp;&nbsp;&nbsp;&nbsp;Administrative expenses | **1846** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Total deductions | **558997** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**Net decrease** | **(190750)** |
| **Net assets available for benefits:** |  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Beginning of year | **1779896** |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**End of year** | $**1589146** |
| The accompanying notes are an integral part of these financial statements. | The accompanying notes are an integral part of these financial statements. |

---

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

**Note 1 Description of the Plan**

The following description of the Telephone and Data Systems, Inc. Tax-Deferred Savings Plan (the Plan) provides only general information. Participants should refer to the Telephone and Data Systems, Inc. Tax-Deferred Savings Plan official plan document or summary plan description for a more complete description of the Plan's provisions.

**General**

The Plan is a contributory tax-qualified profit sharing plan established by Telephone and Data Systems, Inc. (TDS or the Company) and is subject to the provisions of the Employee Retirement Income Security Act of 1974 (ERISA). The Company is the administrator and sponsor of the Plan and The Northern Trust Company (Northern Trust) is the directed trustee and asset custodian of the Plan. Northern Trust also provides record keeping and reporting services to the Plan in conjunction with Alight Solutions (Alight), the Plan's third party administrator. All employees of TDS and its subsidiaries which have adopted the Plan (TDS and such subsidiaries being referred to as employers) whom are age 18 or older generally are eligible to participate. The Plan allows eligible employees to enter the Plan upon the later of 30 days of continuous service with the employers or their 18<sup>th</sup> birthday. Participation in the Plan is voluntary, however, any eligible employee who does not enroll on his or her own, or opt out of automatic enrollment, will be automatically enrolled in the Plan starting on his or her eligibility date (or as soon as practicable thereafter).

On August 1, 2025, United States Cellular Corporation, a subsidiary of TDS, changed its name to Array Digital Infrastructure, Inc. (Array). Array is used throughout this report even when referring to historical periods.

**Contributions**

Participants may contribute to the Plan on a before-tax basis (before-tax contributions) or on a designated Roth basis (after-tax contributions). The combined before-tax and designated Roth contributions may not exceed 60% of the Participant's compensation, as defined in the Plan, or exceed the maximum annual contribution amount per participant set forth in the Internal Revenue Code (IRC). Eligible employees and participants (including terminated participants with a balance in the Plan) may also contribute amounts representing eligible distributions from other eligible retirement plans or individual retirement accounts including the Telephone and Data Systems, Inc. Pension Plan (rollover contributions).

Newly eligible employees are automatically enrolled in the Plan on a before-tax basis at a 6% deferral rate with the rate increasing by 1% annually until it reaches 15%, unless an employee elects otherwise. The Vanguard Target Date Retirement Trusts are used as the Qualified Default Investment Alternative for automatic enrollment. Non-contributing employees may from time to time be re-enrolled unless they make an affirmative election at the time of the re-enrollment not to participate.

Prior to January 1, 2026, the employer matching contribution was 100% of the first 3% of a participant's before-tax and designated Roth contributions and 40% of the next 2% of before-tax and designated Roth contributions. Effective January 1, 2026, the employer matching contribution increased to 100% of the first 3% of a participant's before-tax and designated Roth contributions and 55% of the next 3% of before-tax and designated Roth contributions.

**Participants' Accounts and Investment Options**

Each participant's account is credited with the participant's before-tax and designated Roth contributions, rollover contributions, employer matching contributions and investment income, and reduced by investment losses and fees. The benefit to which a participant is entitled is the benefit that can be provided from the participant's vested account.

The Plan's assets are overseen by the Investment Management Committee. The Investment Management Committee is authorized to select investment options and to invest Plan assets as directed by the participants (or in the absence of such a direction, as determined by the Investment Management Committee). Participants may invest their accounts in a variety of investment options as more fully described in the Plan's summary plan description and other Plan materials. Participants may change their investment elections via telephone or internet. Participants can direct no more than 20% of their contributions into the TDS Common Stock Fund and Array Common Stock Fund on a combined basis.

Effective January 1, 2026, the Plan allows participants to convert certain non-Roth account balances to the Roth (after-tax) account within the Plan.

**Vesting**

Participants are always 100% vested in their before-tax, designated Roth and rollover contributions plus earnings thereon. Vesting in employer matching contributions plus earnings thereon is based on years of vesting service. Employer matching contributions plus earnings thereon vest 34% after the participant completes one year of vesting service; and 100% after the participant completes two years of vesting service.

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

A participant also becomes 100% vested in employer matching contributions plus earnings thereon upon termination of employment after attaining age 65 or due to death or total and permanent disability (as defined in the Plan and determined by the disability insurer).

**Forfeited Accounts**

For the year ended December 31, 2025, forfeited non-vested account balances used to reduce employer contributions were $0.5 million.

**Payment of Benefits**

Vested benefits may be paid to the participant upon termination of employment in the form of a lump sum payment, partial distribution (of not less than $500) or installments. Alternatively, a terminated participant generally may rollover the eligible portion of his or her vested benefits to an eligible retirement plan or individual retirement account. Participants experiencing a qualified financial hardship, who are on a qualified military leave or who have attained age 59½ may withdraw a portion of their vested account balance as defined in the Plan while employed by TDS and its subsidiaries. While employed by TDS and its subsidiaries, participants also may take a distribution of a portion of their vested account following the birth or adoption of their child.

**Notes Receivable from Participants**

Participants may borrow from their Plan accounts a minimum of $1,000 up to a maximum equal to the lesser of $50,000 or 50% of their account balance (excluding employer matching contributions and related earnings). Participants may only have one note outstanding at a time and such note is secured by the remaining balance in the participant's account. The notes bear interest at the prime rate plus 1% as published in the Wall Street Journal on the fifteenth day of the month prior to the quarter in which the note is processed. Principal and interest are generally paid ratably through after-tax payroll deductions. Participants who terminate employment and have an outstanding loan balance generally may continue to make monthly loan repayments following their termination. The repayment period on the note generally ranges from one to five years. Notes are considered delinquent if two consecutive note payments are not received. If the delinquency is not cured, the loan will be considered in default and taxation of the loan balance to the participant will occur.

**Termination of Plan**

Although it has not expressed any intent to do so, the Company has the right under the Plan to terminate the Plan at any time subject to the provisions of ERISA. In the event of Plan termination, participants become 100% vested in their accounts.

On August 1, 2025, Array sold its wireless operations and select spectrum assets to T-Mobile US, Inc. As a result of the sale, the Plan experienced a partial plan termination and affected participants became 100% vested in their accounts.

**Plan Expenses**

Certain recordkeeping and trustee fees, as well as auditing, investment consulting, investment management and participant communications fees, are paid by Plan participants. Plan participants also pay participant-initiated transaction fees (such as distribution, withdrawal, loan and Qualified Domestic Relations Order fees). Legal fees are paid by TDS.

**Note 2 Summary of Significant Accounting Policies** 

**Basis of Accounting and Use of Estimates**

The accompanying financial statements have been prepared on the accrual basis of accounting. The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires the Plan's management to use estimates and assumptions that affect the accompanying financial statements and disclosures. Actual results could differ from these estimates and assumptions.

**Investment Valuation and Income Recognition**

Investments are reported at fair value. See Note 3 – Fair Value Measurements for further information on the fair value of the Plan's investments. The Plan's Investment Management Committee determines the Plan's valuation policies utilizing information provided by the investment advisers and custodians.

Net appreciation in fair value of investments included in the accompanying Statement of Changes in Net Assets Available for Benefits includes realized gains or losses from the sale of investments and unrealized appreciation or depreciation in the fair value of investments. The net realized gains or losses on the sale of investments represent the difference between the sale proceeds and the cost of the investment. Net unrealized appreciation or depreciation in the fair value of investments represents the net change in the fair value of the investments held during the year.

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

Purchases and sales of securities are recorded on a trade date basis. Interest income is recorded on the accrual basis, and dividends are recorded on the ex-dividend date.

**Notes Receivable from Participants**

Notes receivable from participants are measured at their unpaid principal balance plus any accrued but unpaid interest. Interest income is recorded on the accrual basis. Delinquent participant notes are reclassified as distributions in accordance with the terms of the Plan document. Notes receivable from participants have been classified as an investment asset for Form 5500 reporting purposes and, accordingly, have been included as an investment in the supplemental schedule, Schedule H, Line 4i – Schedule of Assets (Held at End of Year).

**Payment of Benefits**

Benefit payments are recorded when paid.

**Risks and Uncertainties** 

The Plan invests in various investment securities, including mutual funds, common/collective trusts, and employer common stock. Investments, in general, are subject to various risks, including credit, interest, and overall market volatility risks. Due to the level of risk associated with certain investment securities, it is reasonably possible that changes in values of investment securities will occur in the near term, and such changes could materially affect participants' account balances and the amounts reported in the Statements of Net Assets Available for Benefits.

**Note 3 Fair Value Measurements**

Fair value is a market based measurement and not an entity specific measurement, based on an exchange transaction in which the entity sells an asset or transfers a liability (exit price) in an orderly transaction between market participants.

The provisions of GAAP establish a fair value hierarchy that contains three levels for inputs used in fair value measurements.

Level 1 - inputs include quoted market prices for identical assets or liabilities in active markets.

Level 2 - inputs include quoted market prices for similar assets or liabilities in active markets or quoted market prices for identical assets or liabilities in inactive markets.

Level 3 - inputs are unobservable.

A financial instrument's level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. A financial instrument's level within the fair value hierarchy is not representative of its expected performance or its overall risk profile and, therefore, Level 3 assets are not necessarily higher risk than Level 2 assets or Level 1 assets. As of December 31, 2025 and 2024, the Plan held no Level 2 or Level 3 assets. The following is a description of the valuation methodologies used for instruments measured at fair value, including the general classification of such instruments pursuant to the valuation hierarchy.

The Plan values shares of TDS Common Stock and Array Common Stock based on the closing price reported in the active market in which the securities are traded. These securities are classified as Common Stock of the Plan Sponsor and Subsidiary. The Plan also values mutual funds based on the closing price reported in the active market in which the individual securities are traded.

------

<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

The following tables set forth by level, within the fair value hierarchy, the Plan's investments at fair value as of December 31, 2025 and 2024, respectively.

---

| | | |
|:---|:---|:---|
| **December 31, 2025** | **Level 1** | **Total** |
| (Dollars in thousands) |  |  |
| Mutual Funds | $451942 | $451942 |
| Common Stock of Plan Sponsor and Subsidiary | 24348 | 24348 |
| &nbsp;&nbsp;&nbsp;&nbsp;Total investments in the fair value hierarchy | $476290 | $476290 |
| Common/Collective Trusts measured at net asset value |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Target retirement<sup>(1)</sup> |  | 536203 |
| &nbsp;&nbsp;&nbsp;&nbsp;Bond<sup>(2)</sup> |  | 94536 |
| &nbsp;&nbsp;&nbsp;&nbsp;Investment contracts<sup>(3)</sup> |  | 95793 |
| &nbsp;&nbsp;&nbsp;&nbsp;Equity<sup>(4) (5)</sup> |  | 376354 |
| &nbsp;&nbsp;&nbsp;&nbsp;**Total investments at fair value** |  | $**1579176** |
| **December 31, 2024** | Level 1 | Total |
| (Dollars in thousands) |  |  |
| Mutual Funds | $526725 | $526725 |
| Common Stock of Plan Sponsor and Subsidiary | 30654 | 30654 |
| &nbsp;&nbsp;&nbsp;&nbsp;Total investments in the fair value hierarchy | $557379 | $557379 |
| Common/Collective Trusts measured at net asset value |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Target retirement<sup>(1)</sup> |  | 562207 |
| &nbsp;&nbsp;&nbsp;&nbsp;Bond<sup>(2)</sup> |  | 111091 |
| &nbsp;&nbsp;&nbsp;&nbsp;Investment contracts<sup>(3)</sup> |  | 105104 |
| &nbsp;&nbsp;&nbsp;&nbsp;Equity<sup>(4) (5)</sup> |  | 426702 |
| &nbsp;&nbsp;&nbsp;&nbsp;Total investments at fair value |  | $1762483 |
| <sup>(1)</sup> The Vanguard Target Retirement Trusts invest mainly in mutual funds with the remainder invested in money market funds. The fair value of these trusts is calculated using the market approach which values the underlying investments of the trust based on observable market prices. These trusts are measured at fair value based on the NAV per share. | <sup>(1)</sup> The Vanguard Target Retirement Trusts invest mainly in mutual funds with the remainder invested in money market funds. The fair value of these trusts is calculated using the market approach which values the underlying investments of the trust based on observable market prices. These trusts are measured at fair value based on the NAV per share. | <sup>(1)</sup> The Vanguard Target Retirement Trusts invest mainly in mutual funds with the remainder invested in money market funds. The fair value of these trusts is calculated using the market approach which values the underlying investments of the trust based on observable market prices. These trusts are measured at fair value based on the NAV per share. |
| <sup>(2)</sup> The BlackRock Intermediate Government/Credit Bond Index Fund F (BlackRock Bond Fund) is a bank maintained collective investment fund that invests in bond index funds and other short-term investments. The fair value is calculated using the market approach which values the underlying investments in the fund using observable inputs for similar assets. The BlackRock Bond Fund is measured at fair value based on the NAV per share. | <sup>(2)</sup> The BlackRock Intermediate Government/Credit Bond Index Fund F (BlackRock Bond Fund) is a bank maintained collective investment fund that invests in bond index funds and other short-term investments. The fair value is calculated using the market approach which values the underlying investments in the fund using observable inputs for similar assets. The BlackRock Bond Fund is measured at fair value based on the NAV per share. | <sup>(2)</sup> The BlackRock Intermediate Government/Credit Bond Index Fund F (BlackRock Bond Fund) is a bank maintained collective investment fund that invests in bond index funds and other short-term investments. The fair value is calculated using the market approach which values the underlying investments in the fund using observable inputs for similar assets. The BlackRock Bond Fund is measured at fair value based on the NAV per share. |
| <sup>(3)</sup> The Vanguard Retirement Savings Trust II is a collective trust that invests in the Vanguard Retirement Savings Master Trust, which invests in traditional and synthetic investment contracts backed by investments issued by insurance companies and banks. The fair value is determined based on the underlying investments of the common trust as traded in active markets or valued using significant observable inputs. The NAV for the investment contracts is $1 per share. | <sup>(3)</sup> The Vanguard Retirement Savings Trust II is a collective trust that invests in the Vanguard Retirement Savings Master Trust, which invests in traditional and synthetic investment contracts backed by investments issued by insurance companies and banks. The fair value is determined based on the underlying investments of the common trust as traded in active markets or valued using significant observable inputs. The NAV for the investment contracts is $1 per share. | <sup>(3)</sup> The Vanguard Retirement Savings Trust II is a collective trust that invests in the Vanguard Retirement Savings Master Trust, which invests in traditional and synthetic investment contracts backed by investments issued by insurance companies and banks. The fair value is determined based on the underlying investments of the common trust as traded in active markets or valued using significant observable inputs. The NAV for the investment contracts is $1 per share. |
| <sup>(4)</sup> The Vanguard Institutional 500 Index Trust seeks to track the performance of a benchmark index that measures the investment return of large-capitalization stocks. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. | <sup>(4)</sup> The Vanguard Institutional 500 Index Trust seeks to track the performance of a benchmark index that measures the investment return of large-capitalization stocks. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. | <sup>(4)</sup> The Vanguard Institutional 500 Index Trust seeks to track the performance of a benchmark index that measures the investment return of large-capitalization stocks. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. |
| <sup>(5)</sup> The Vanguard Institutional Total International Stock Market Index Trust seeks to track the performance of a benchmark index that measures the investment return of stocks issued by companies located in developed and emerging markets, excluding the United States. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. | <sup>(5)</sup> The Vanguard Institutional Total International Stock Market Index Trust seeks to track the performance of a benchmark index that measures the investment return of stocks issued by companies located in developed and emerging markets, excluding the United States. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. | <sup>(5)</sup> The Vanguard Institutional Total International Stock Market Index Trust seeks to track the performance of a benchmark index that measures the investment return of stocks issued by companies located in developed and emerging markets, excluding the United States. The fair value is calculated using the market approach which values the underlying investments of the trust based on observable market prices. This trust is measured at fair value based on the NAV per share. |

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<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

The following tables summarize the Plan's investments that are measured at fair value based on the net asset value per share as of December 31, 2025 and 2024, respectively.

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| | | | | |
|:---|:---|:---|:---|:---|
| **December 31, 2025** | **Fair Value** | **Unfunded Commitments** | **Participant Redemption Frequency** | **Redemption Notice Period** |
| (Dollars in thousands) |  |  |  |  |
| Common/Collective Trusts |  |  |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Target retirement | $536203 | $— | Daily | One month |
| &nbsp;&nbsp;&nbsp;&nbsp;Bond | 94536 |  | Daily | One month |
| &nbsp;&nbsp;&nbsp;&nbsp;Investment contracts | 95793 |  | Daily | Twelve months |
| &nbsp;&nbsp;&nbsp;&nbsp;Equity | 376354 |  | Daily | One month |
| December 31, 2024 | Fair Value | Unfunded Commitments | Participant Redemption Frequency | Redemption Notice Period |
| (Dollars in thousands) |  |  |  |  |
| Common/Collective Trusts |  |  |  |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Target retirement | $562207 | $— | Daily | One month |
| &nbsp;&nbsp;&nbsp;&nbsp;Bond | 111091 |  | Daily | One month |
| &nbsp;&nbsp;&nbsp;&nbsp;Investment contracts | 105104 |  | Daily | Twelve months |
| &nbsp;&nbsp;&nbsp;&nbsp;Equity | 426702 |  | Daily | One month |

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**Note 4 Parties-in-Interest**

Transactions between the Plan and certain parties meet the definition of parties-in-interest transactions under the provisions of ERISA (Parties-in-interest transactions).

Transactions with Northern Trust, the directed trustee of the Plan, Alight, provider of certain reporting and administrative services to the Plan, and BlackRock Institutional Trust Company, National Association (BlackRock), provider of investment management services, are Parties-in-interest transactions. The aggregate cost of trustee, administrative and investment management charges to the Plan by Northern Trust, Alight, and BlackRock was $1.8 million for the year ended December 31, 2025.

The Plan made participant-directed purchases of $7.8 million and sales of $12.9 million of TDS and Array Common Stock on an aggregate basis for the year ended December 31, 2025, which are Parties-in-interest transactions.

Outstanding Notes receivable from participants, and the related interest income on Notes receivable from participants, for the year ended December 31, 2025 are presented on the Statements of Net Assets Available for Benefits and the Statement of Changes in Net Assets Available for Benefits, respectively.

**Note 5 Tax Status**

The Plan obtained its latest determination letter on February 25, 2015 in which the Internal Revenue Service stated that the Plan, as designed, complied with the applicable requirements of the IRC, and the related trust was exempt from taxation. The Plan has been amended since the receipt of the determination letter. The Plan Administrator believes that the Plan is designed and being operated in material compliance with the applicable requirements of the IRC. Therefore, the Plan Administrator believes that the Plan was qualified and the related trust was tax-exempt as of December 31, 2025.

Management evaluated the Plan's tax positions and the Plan took no uncertain tax positions that require adjustment to the financial statements. Therefore, no provision or liability for income taxes has been included in the financial statements as of December 31, 2025 or 2024. The Plan is subject to audits by taxing jurisdictions; however, for tax periods in progress, there have been no such audits.

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<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Telephone and Data Systems, Inc.**

**Tax-Deferred Savings Plan**

**December 31, 2025 and 2024** 

**Notes to Financial Statements** 

**Note 6 Reconciliation of Financial Statements to Form 5500**

A reconciliation between the financial statements and Form 5500 as of December 31, 2025 and 2024 is as follows:

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| | | |
|:---|:---|:---|
| (Dollars in thousands) | **2025** | 2024 |
| Total net assets per Form 5500, Schedule H | $**1589076** | $1779890 |
| Deemed distributions of notes receivable from participants | **70** | 6 |
| &nbsp;&nbsp;&nbsp;&nbsp;Net Assets Available for Benefits Per Financial Statements | $**1589146** | $1779896 |
| Change in net assets per Form 5500, Schedule H | $**(190814)** |  |
| Change in deemed distributions of notes receivable from participants | **64** |  |
| &nbsp;&nbsp;&nbsp;&nbsp;Changes in Net Assets Available for Benefits Per Financial Statements | $**(190750)** |  |

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**Note 7 Subsequent Events**

The Plan's management evaluated subsequent events from December 31, 2025 through June 2, 2026, the date these financial statements were issued. There have been no significant subsequent events during this period that require adjustments to or disclosure in the financial statements as of December 31, 2025 and for the year then ended.

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<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

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| | | | | |
|:---|:---|:---|:---|:---|
| **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** | **Telephone and Data Systems, Inc.** |
| **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** | **Tax-Deferred Savings Plan** |
| **Schedule H, Line 4i - Schedule of Assets (Held at End of Year)** | **Schedule H, Line 4i - Schedule of Assets (Held at End of Year)** | **Schedule H, Line 4i - Schedule of Assets (Held at End of Year)** | **Schedule H, Line 4i - Schedule of Assets (Held at End of Year)** | **Schedule H, Line 4i - Schedule of Assets (Held at End of Year)** |
| **Plan 003 EIN 36-2669023** | **Plan 003 EIN 36-2669023** | **Plan 003 EIN 36-2669023** | **Plan 003 EIN 36-2669023** | **Plan 003 EIN 36-2669023** |
| **December 31, 2025** | **December 31, 2025** | **December 31, 2025** | **December 31, 2025** | **December 31, 2025** |
| (Dollars in thousands) | (Dollars in thousands) | (Dollars in thousands) | (Dollars in thousands) | (Dollars in thousands) |
| **(a)** | **(b)** | **(c)** | **(d)** | **(e)** |
|  | **Identity of Issue, Borrower, Lessor, or Similar Party** | **Description of Investment Including Maturity Date,<br>Rate of Interest, Collateral, Par or Maturity Value** | **Cost** | **Current Value** |
|  | **Common/Collective Trusts** |  |  |  |
|  | Vanguard | Retirement Savings Trust II | \*\* | $95793 |
|  | Vanguard | Target Retirement Income and Growth Trust I | \*\* | 3348 |
|  | Vanguard | Target Retirement Income Trust I | \*\* | 11368 |
|  | Vanguard | Target 2020 Retirement Trust I | \*\* | 11862 |
|  | Vanguard | Target 2025 Retirement Trust I | \*\* | 33623 |
|  | Vanguard | Target 2030 Retirement Trust I | \*\* | 64635 |
|  | Vanguard | Target 2035 Retirement Trust I | \*\* | 83615 |
|  | Vanguard | Target 2040 Retirement Trust I | \*\* | 75220 |
|  | Vanguard | Target 2045 Retirement Trust I | \*\* | 88822 |
|  | Vanguard | Target 2050 Retirement Trust I | \*\* | 80277 |
|  | Vanguard | Target 2055 Retirement Trust I | \*\* | 47991 |
|  | Vanguard | Target 2060 Retirement Trust I | \*\* | 24422 |
|  | Vanguard | Target 2065 Retirement Trust I | \*\* | 8404 |
|  | Vanguard | Target 2070 Retirement Trust I | \*\* | 2616 |
|  | Vanguard | Institutional 500 Index Trust | \*\* | 226315 |
|  | Vanguard | Institutional Total International Stock Market Index Trust | \*\* | 150039 |
| \* | BlackRock | Intermediate Government/Credit Bond Index Fund F | \*\* | 94536 |
|  | **Total Common/Collective Trusts** |  |  | 1102886 |
|  | **Common Stock of Plan Sponsor and Subsidiary** | **Common Stock of Plan Sponsor and Subsidiary** |  |  |
| \* | Telephone and Data Systems, Inc. | Common Stock Fund | \*\* | 13762 |
| \* | Array Digital Infrastructure, Inc. | Common Stock Fund | \*\* | 10586 |
|  | **Total Common Stock of Plan Sponsor and Subsidiary** | **Total Common Stock of Plan Sponsor and Subsidiary** |  | 24348 |
|  | **Mutual Funds** |  |  |  |
|  | Vanguard | Small Cap Value Index Fund | \*\* | 68628 |
|  | Vanguard | Value Index Fund | \*\* | 96337 |
|  | Vanguard | Small Cap Growth Index Fund | \*\* | 59080 |
|  | Vanguard | Growth Index Fund | \*\* | 227787 |
| \* | Northern Institutional Funds | U.S. Government Select Portfolio | \*\* | 110 |
|  | **Total Mutual Funds** |  |  | 451942 |
| \* | Participant Loans | Interest rates range from 4.25% to 9.50%, maturing through December 2030 | Interest rates range from 4.25% to 9.50%, maturing through December 2030 | 8139 |
|  |  |  |  | $1587315 |
| \* Represents a party-in-interest, as defined by ERISA. | \* Represents a party-in-interest, as defined by ERISA. | \* Represents a party-in-interest, as defined by ERISA. |  |  |
| \*\* The cost of participant-directed investments is not required to be disclosed. | \*\* The cost of participant-directed investments is not required to be disclosed. | \*\* The cost of participant-directed investments is not required to be disclosed. |  |  |

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<u>[**Table of Contents**](#i77f39d4b9ab146d998694527a60dead3_4)</u>

**Exhibits**

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| | |
|:---|:---|
| **Exhibit Number** | **Description of Documents** |
| Exhibit 23 | <u>[Consent of Independent Registered Public Accounting Firm - BDO USA, P.C.](tds202511-kexhibit23.htm)</u> |

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**Signatures**

Pursuant to the requirements of the Securities and Exchange Act of 1934, Telephone and Data Systems, Inc., the Plan Administrator, has duly caused this Annual Report on Form 11-K to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | | |
|:---|:---|:---|:---|
| | | **TELEPHONE AND DATA SYSTEMS, INC.** | **TELEPHONE AND DATA SYSTEMS, INC.** |
| | | **TAX-DEFERRED SAVINGS PLAN** | **TAX-DEFERRED SAVINGS PLAN** |
| | | By: | /s/ Anita J. Kroll |
| | | | Anita J. Kroll |
| | | | Vice President - Controller and Chief Accounting Officer |
| Dated: | June 2, 2026 |  |  |

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## Ex-23

**Exhibit 23**

BDO USA, P.C.

**Consent of Independent Registered Public Accounting Firm**

Telephone and Data Systems, Inc. Tax-Deferred Savings Plan

Madison, Wisconsin

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 333-266692) of Telephone and Data Systems, Inc. and on Form S-8 (No. 333-266693) of Array Digital Infrastructure, Inc. (formerly known as United States Cellular Corporation) of our report dated June 2, 2026, relating to the financial statements and supplemental schedule of Telephone and Data Systems, Inc. Tax-Deferred Savings Plan which appear in this Form 11-K for the year ended December 31, 2025.

/s/ BDO USA, P.C.

Madison, Wisconsin

June 2, 2026

<br>