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Service Computation Date (SCD)
Calculate all four federal service computation dates — Leave SCD, FERS Retirement SCD, TSP SCD, and RIF SCD — in one place. Handles military service, deposit rules, military retiree restrictions, and performance-rating credit.
Reviewed by Jonathan D., 20-year federal employee · Formulas verified against OPM.gov ·
Editorial note — estimate, not official HR determination
SCD calculations depend on records only your HR Benefits Officer can verify — your complete SF-50 history, DD-214, deposit receipts, and LWOP logs. This tool provides an educational estimate. Verify exact dates in your eOPF or with HR before making retirement or RIF decisions. This is not financial, legal, or HR advice.
Estimate — verify with your agency HR office
SCD calculations depend on official records (SF-50 history, DD-214, deposit receipts, LWOP logs) that only your HR Benefits Officer can verify. This tool provides an educational estimate. Use it to understand your situation; confirm exact dates in your eOPF or with HR before making retirement decisions.
Civilian Service Periods
Enter each contiguous block of federal civilian service. Separations create gaps — add one row per continuous appointment.
Period 1
Leave blank / use today if currently employed
Military Service Periods (optional)
Active duty service only. Reserve/Guard drill days are generally not creditable unless activated.
Additional Options
Used for RIF SCD only (5 CFR §351.504). If you have multiple recent ratings, the agency averages them — this tool uses your current single-level selection as an estimate. Consult your HR office for the multi-rating calculation.
Affects TSP vesting period only.
Use today if currently employed. Use your separation date if you have left federal service.
The four service computation dates — what each one governs
Federal employees are assigned up to four different service computation dates, each governing a different benefit system. They can differ from each other by years — and getting one wrong has compounding consequences.
The four federal service computation date types and their governing laws
SCD Type
Authority
What it governs
Military credit rule
Leave SCD
5 U.S.C. §6303
Annual leave accrual tier (4 / 6 / 8 hrs/pp)
All active duty (non-retirees) without deposit
Retirement SCD
5 U.S.C. §8412
FERS eligibility + annuity computation service figure
Deposit paid only (or retired-pay waiver)
TSP SCD
5 CFR §1603 / TSP Bulletin 15-1
Vesting of Agency Automatic 1% contributions
Civilian service only; floor at 1984-01-01
RIF SCD
5 CFR §351.503–504
Retention standing in reductions in force
Leave SCD + performance-rating years
Source: OPM GPPA Chapter 6, OPM FERS Creditable Service, TSP.gov Bulletin 15-1, 5 CFR Part 351. Reviewed August 2026.
Leave SCD: the one on every SF-50
Your Leave SCD appears in Block 31 of every SF-50 Notification of Personnel Action. It determines which of three accrual tiers you are in — 4, 6, or 8 hours of annual leave per biweekly pay period. Almost all federal civilian service is creditable here, and for most non-military-retiree employees, active duty military service counts too — no deposit required.
The exception that trips up many employees: if you receive military retired pay, the statute (5 U.S.C. §6303(e)) restricts your Leave SCD credit to service during a declared war, an authorized campaign or expedition, or a disability connected to armed conflict. Waiving your retired pay does not remove this restriction — that is a common misconception verified in OPM guidance. Waiving retired pay helps your Retirement SCD only.
Retirement SCD: the deposit difference
Your FERS Retirement SCD determines when you become eligible to retire and how many service years go into your annuity formula. Civilian service accrues the same way as it does for Leave SCD. Military service, however, requires a paid deposit — 3% of your military basic pay plus interest — before it counts. If the deposit is unpaid, those active-duty years are excluded from your retirement SCD entirely.
Military retirees who have waived their retired pay can credit all military service toward their FERS retirement — unlike Leave SCD, where the waiver has no effect. The waiver must be submitted to DFAS at least 90 days before your planned civilian retirement. See the Military Buyback Calculator to estimate the deposit cost.
TSP SCD: what you lose if you leave too early
Your TSP Service Computation Date governs vesting of the Agency Automatic 1% Contributions — the 1% of salary deposited into your TSP every pay period regardless of whether you contribute. If you leave federal service before vesting, those contributions and their earnings are forfeited. Employee contributions and matching contributions vest immediately.
Most FERS employees need 3 years of service to vest. Noncareer SES employees, Executive Level positions, and Congressional employees vest in 2 years. The TSP-SCD includes all federal civilian service — not just the period while you were enrolled in TSP — but cannot go earlier than January 1, 1984, per TSP regulations (TSP.gov Bulletin 15-1).
RIF SCD: how performance credit shifts your standing
In a reduction in force, agencies rank employees on a “retention register” by competitive level, tenure, veterans' preference, and seniority. Seniority is measured by your RIF SCD — and the earlier your RIF SCD, the higher your standing. The RIF SCD starts with your Leave SCD and then shifts backward by performance-credit years under 5 CFR §351.504.
When multiple ratings of record are used, agencies average the applicable ratings and round any fraction up to the next whole year. This calculator uses a single-rating estimate — if your agency averages multiple recent ratings, the result could differ. A Level 5 rating adds 20 years of seniority credit; Level 4 adds 16; Level 3 adds 12; Level 2 or below adds nothing.
Rules change September 2, 2026: the years-added credit shown here reflects the framework in effect through September 1, 2026. OPM's final RIF rules (FR 2026-15665, published August 3) take effect September 2 and replace this credit with a performance-point system (your three most recent ratings, scored 7/5/3/0). If you face an actual RIF, verify your retention standing with your agency HR office. See our RIF rules update for details.
LWOP, part-time, and other nuances
Leave without pay (LWOP) exceeding 6 months of aggregate nonpay status in a single calendar year is not creditable service. The excess days are subtracted from your SCD. This calculator flags LWOP periods but cannot precisely compute the reduction without exact hour records — verify with your HR office.
Part-time employment does not change your SCD date — the SCD is computed using calendar days, not hours worked. Part-time schedules do, however, affect the amount of leave you earn per pay period (prorated by hours in pay status) and can affect your annuity computation under FERS.
Frequently asked questions
A Service Computation Date is a constructed date that represents the "effective start" of your federal service for a specific purpose. The further back in time your SCD is, the more seniority or benefits you have accumulated. There are four main SCDs: Leave SCD (annual leave accrual rate), Retirement SCD (FERS eligibility and annuity computation), TSP SCD (vesting of Agency Automatic 1% Contributions), and RIF SCD (retention standing in a reduction in force).
If you are not a military retiree, all active duty military service counts toward your Leave SCD — you do not need to pay a deposit. If you are a military retiree, the statute (5 U.S.C. §6303(e)) limits credit to service during a declared war, an authorized campaign or expedition, or disability retirement connected to armed conflict. Waiving your military retired pay does NOT change this restriction for Leave SCD purposes.
Yes. For post-1956 military service to count toward your FERS Retirement SCD (and annuity), you must pay a deposit equal to 3% of your military basic pay plus interest. Use Form SF-3108 or OPM-1515 to apply. If you are a military retiree, you can instead waive your military retired pay — waiving restores full military credit for Retirement SCD (unlike Leave SCD, where the restriction is statutory and cannot be waived).
Your Leave SCD determines how many hours of annual leave you earn per biweekly pay period: 4 hours (under 3 years), 6 hours (3–14 years), or 8 hours (15+ years). Your Retirement SCD affects your FERS eligibility thresholds and the service-years figure used in your pension formula. The two SCDs often differ because military service requires a paid deposit for Retirement SCD credit but not for Leave SCD credit.
Your Leave SCD determines which of three tiers you are in: fewer than 3 years of leave-SCD service = 4 hours per pay period; 3 to 14 years = 6 hours per pay period; 15 or more years = 8 hours per pay period. The anniversary that triggers a tier increase is calculated from your Leave SCD — for example, if your Leave SCD is January 1, 2015, you crossed the 8-hour tier on January 1, 2030.
Your RIF SCD starts with your Leave SCD and then shifts earlier by additional years based on your most recent performance rating under 5 CFR 351.504: Level 5 (Outstanding) adds 20 years, Level 4 adds 16, Level 3 adds 12, and Level 2 or below adds nothing. Note the deadline: this framework applies through September 1, 2026. OPM final rules effective September 2, 2026 replace the years-added credit with a performance-point system, so verify your retention standing with your agency HR office before relying on any RIF SCD calculation.