FRTIB Thrift Savings Plan Administration — Account Operations, Share Price Calculation, and Participant Statement Rules

Legal Authority

• 5 U.S.C. § 8474 — Federal Retirement Thrift Investment Board authority: establishes the FRTIB as an independent agency to administer the Thrift Savings Plan for federal civilian employees and uniformed service members; authorizes the Board to invest TSP assets and adopt implementing regulations
• 5 U.S.C. § 8439 — Account operations: governs TSP account transactions, share price calculation, contribution allocations, and fund options; the statutory basis for the FRTIB rules in 5 CFR Parts 1640, 1645, and 1690
• 5 CFR Parts 1640, 1645, 1690 — FRTIB regulations governing TSP account operations (withdrawals and loans), share price calculation, and participant statement requirements

Key Mechanics

The Thrift Savings Plan (TSP) is the federal government's defined-contribution retirement plan — the largest defined-contribution plan in the world by assets, with over $800 billion in assets and 6+ million participants. The FRTIB administers the TSP as an independent agency; its fiduciary duty runs to participants, not to the employing agencies or OMB. Share prices for each TSP fund are calculated daily using the net asset value of the underlying investment pool. Participants receive quarterly statements and can access account information online. The TSP offers five core index funds (G, F, C, S, I) and 10 Lifecycle (L) funds that automatically adjust allocation as the target date approaches; the Mutual Fund Window (added 2022) allows participants to invest in non-TSP mutual funds through a brokerage-style interface. Rules governing withdrawals (5 CFR Part 1650), in-service loans (5 CFR Part 1655), and contribution elections (5 CFR Part 1600) govern participants' access to their accounts during and after federal service.

Current Rule (2026)

What This Rule Does

The Federal Retirement Thrift Investment Board (FRTIB) administers the Thrift Savings Plan — the defined-contribution retirement plan for federal civilian employees and members of the uniformed services. Three CFR Parts govern the internal operations of how TSP accounts work, how share prices are calculated, and how participants receive account statements:

• 5 CFR Part 1640 sets the rules for periodic participant statements
• 5 CFR Part 1645 establishes how share prices for each TSP investment fund are calculated each business day
• 5 CFR Part 1690 is the comprehensive general regulation covering account operations, plan definitions, plan year, legal authority for account management (powers of attorney, court orders), and administrative procedures

Together these three Parts govern the day-to-day mechanics of how 7+ million federal employees and service members hold, manage, and access their TSP accounts.

Key Provisions — 5 CFR Part 1690 (General TSP Administration)

• § 1690.1 — Definitions: defines all key TSP terms including the C Fund (Common Stock), F Fund (Fixed Income), G Fund (Government Securities), I Fund (International Stock), S Fund (Small Cap Stock), and L Funds (Lifecycle Funds); defines basic pay for contribution purposes; defines traditional contributions (pre-tax), Roth contributions (after-tax), catch-up contributions (for participants 50+), agency automatic (1%) contributions, and agency matching contributions; defines participant, beneficiary participant, and plan participant categories; defines the TSP record keeper (Alight Solutions), the ThriftLine, and the TSP website
• § 1690.2 — Plan year: the TSP operates on a calendar year (January 1 through December 31) for all purposes where federal law does not require a different basis
• § 1690.3 — Powers of attorney: participants and beneficiaries may appoint an attorney-in-fact to manage their TSP accounts; the TSP record keeper must approve the power of attorney before the agent can act; a general POA grants unlimited TSP account authority; a specific POA grants authority only for specifically described transactions; the POA must be signed by the participant, identify both parties with addresses, meet state law requirements of the participant's domicile, and be a complete document
• § 1690.4 — Court-ordered guardianship: a guardian or conservator appointed by a court of competent jurisdiction may conduct TSP business on behalf of an incapacitated participant; the court order must be approved by the TSP record keeper before the agent can act; general grants of guardianship authority give the guardian unlimited TSP account access; specific grants limit the guardian to expressly described transactions; agents must demonstrate they meet any court-specified preconditions (e.g., bonding requirements)
• § 1690.5 — Negotiated instruments: the TSP does not accept partial payment offers or restrictive-legend instruments (e.g., checks marked "payment in full") as settlement of amounts owed; the TSP record keeper maintains a dedicated payment address that does not accept general correspondence
• § 1690.6 — Account freezes: the TSP record keeper may freeze an account pursuant to a qualifying retirement benefits court order (Part 1653), a DOJ Mandatory Victims Restitution Act request, upon a participant's death, upon suspicion of fraud or identity theft, in response to litigation, for operational reasons (correcting processing errors), at the participant's own written request, or for any other reason necessary to maintain account integrity or comply with law

Key Provisions — 5 CFR Part 1645 (Share Price Calculation)

• § 1645.1 — Definitions: "accrued" means income recognized when earned and expenses when incurred; "administrative expenses" are expenses described in 5 U.S.C. § 8437(c)(3) (expenses of administering the TSP investment funds); "basis" is the number of shares of a fund used to calculate the share price; "business day" is any calendar day for which share prices are calculated; "forfeitures" are amounts forfeited to the TSP under 5 U.S.C. § 8432(g)(2)
• § 1645.2 — Posting of transactions: each business day the TSP record keeper calculates a share price for each investment fund reflecting that day's investment performance, after deducting administrative expenses; transactions submitted by the applicable deadline are processed at that day's share price; late submissions are processed at the next business day's price

Key Provisions — 5 CFR Part 1640 (Periodic Participant Statements)

Part 1640 provides participants with regular account statements showing contributions, agency contributions, investment returns, and account balances by fund. Statement frequency and format requirements are established by FRTIB. Definitions used in Part 1640 point to the comprehensive definitions in 5 CFR 1690.1. Major changes to statement format and delivery were published in 2022 (87 FR 31680).

How It Affects You

Federal civilian employees and uniformed service members enrolled in TSP should understand that their accounts operate through a record-keeper system managed by FRTIB. The share prices posted each business day determine the value of your account — if you submit a fund transfer or withdrawal request before the daily deadline, it processes at that day's price; after the deadline, it prices at the next business day's close.

Powers of attorney for TSP must be specifically approved by the record keeper before your agent can act. If you are setting up financial planning authority for a family member or financial advisor to access your TSP, submitting the POA form through the TSP website is required — a standard financial POA alone is not sufficient until approved. Processing can take several weeks.

Guardianship orders covering TSP accounts must be submitted to and approved by the record keeper before the guardian can transact. If you are the legal guardian for an incapacitated federal employee, ensure your court order is specific enough about TSP authority — "guardian of the estate" language typically qualifies, but narrow conservatorship orders may need clarification before FRTIB will approve them.

Account freezes can occur for reasons outside the participant's control — including litigation involving the account or law enforcement holds. If your TSP account appears frozen, contact the TSP record keeper (the ThriftLine: 1-877-968-3778) to determine the reason and expected duration.

Catch-up contributions (for participants age 50 and older) allow additional contributions beyond the IRS 402(g) elective deferral limit. These are tracked separately and posted according to the same share-price and deadline rules as regular contributions.

Implementing Regulations — Vesting

The vesting rules for TSP are at 5 CFR Part 1603 — Vesting. Key provisions:

• § 1603.1 — Definitions: "civilian service" means non-military service creditable under CSRS or FERS (5 U.S.C. chapters 83/84), determined without regard to deposit requirements or time limitations; "uniformed service" means service creditable under 10 U.S.C. § 1331 or similar military retirement statutes
• § 1603.2 — Basic vesting rules: CSRS employees are immediately vested in all amounts in their TSP accounts; FERS employees and uniformed service members are immediately vested in their own contributions and agency matching contributions from day one — but Agency Automatic (1%) Contributions and their attributable earnings vest only after completing the required civilian service
• § 1603.3 — Service requirements: FERS employees vest in Agency Automatic (1%) Contributions after completing 3 years of civilian service; certain employees (congressional employees, FLEO-covered employees) have modified vesting schedules under paragraph (b); if a FERS employee separates before meeting the service requirement, unvested Agency Automatic (1%) Contributions and attributable earnings are forfeited to the TSP

The practical effect: a FERS employee who leaves federal service in fewer than 3 years will lose any Agency Automatic (1%) contributions their agency deposited on their behalf, along with the earnings those contributions generated. Their own contributions (both traditional and Roth) and any agency matching contributions are already vested and are not forfeited.

Statutory Authority

This rule implements:

• 5 U.S.C. § 8474 — Federal Retirement Thrift Investment Board; authorizes FRTIB to establish and administer the Thrift Savings Fund and to prescribe regulations governing TSP operations
• 5 U.S.C. § 8439 — Investment of Thrift Savings Fund; establishes the investment fund structure for TSP and authorizes FRTIB to calculate and post share prices and provide participant statements
• 5 U.S.C. § 8432 — Contributions to the Thrift Savings Plan; authorizes Agency Automatic (1%) and agency matching contributions and establishes the statutory framework for vesting requirements

Recent Rulemakings

Major revisions to Parts 1640, 1645, and 1690 were published in 2022 (87 FR 31680, 87 FR 31695, 87 FR 31696) — the updates reflected changes in TSP record-keeping services following FRTIB's transition to a new record-keeper (Alight Solutions) and the rollout of a new TSP participant website and mobile platform. Earlier amendments addressed the introduction of Roth TSP contributions (2012) and changes to mutual fund windows.

Pending Action