Short answer: when you retire you can buy 1 to 60 whole months of extra Washington TRS service. Each month adds to the formula, so your pension goes up, but bought months don't help you qualify for retirement sooner. Service you withdrew can be bought back; see leaving teaching. Compare with working one more year, or run the calculator.
Buying months at retirement
At retirement you can buy 1 to 60 whole months of additional service credit (an annuity). It increases your monthly benefit by the plan formula but cannot be used to qualify for retirement. Cost = monthly increase / administrative factor for your age and plan. Pay in full within 90 days of the bill. DRS TRS23RAPP 11/2022, p. 12, Can I purchase additional service credit?; RCW 41.32.066; DRS Washington TRS Plan 2 page, Purchase service credit annuity
| Months | Adds a month | Cost (application's factor) | Cost (2026 factor) |
|---|---|---|---|
| 10 | $50 | $7,164 | $9,281 |
| 20 | $100 | $14,327 | $18,562 |
| 30 | $150 | $21,491 | $27,843 |
| 40 | $200 | $28,654 | $37,124 |
| 50 | $250 | $35,818 | $46,405 |
| 60 | $300 | $42,981 | $55,687 |
The application calls its factor (0.0069798) illustrative. DRS's 2026 administrative factors give 0.0053873 for Plans 2 and 3 at exactly 65 (0.0070518 for Plan 1), which makes the same purchase cost more. DRS TRS23RAPP 11/2022, p. 12, Purchasing service credit in 10-month increments / Example for a 65-year-old Washington TRS member; DRS Administrative Factors workbook 2026, sheet Appx D (PAA-PSC), Washington TRS 1 and Washington TRS 2/3 purchase factors by age
Cost of $100 a month more, by age (2026, Plans 2 and 3)
| Age | Factor | Cost |
|---|---|---|
| 55 | 0.0045842 | $21,814 |
| 60 | 0.0049244 | $20,307 |
| 62 | 0.0050951 | $19,627 |
| 65 | 0.0053873 | $18,562 |
| 67 | 0.0056224 | $17,786 |
| 70 | 0.0060453 | $16,542 |
The older you are when you buy, the less it costs, because the pension is paid for fewer years.
Other service you may be able to add
- Plan annuity. Washington TRS members can also buy a Washington TRS plan annuity at retirement with their own funds (not Plan 3 contributions), no minimum or maximum; cash/check limited to 100% of salary or $72,000 in 2026, whichever is less. DRS Washington TRS Plan 1 page, Washington TRS plan annuity FAQ
- Withdrawn service. Plan 1/2 members who withdrew and return can restore service by repaying withdrawn contributions plus interest (deadlines apply); later purchases cost more. DRS Washington TRS Plan 1 page, Returning to public service; RCW 41.32.064
- Military service. Up to five years of interruptive military service (sometimes up to 10); service during a war or with a campaign/expeditionary medal may be free; otherwise pay within five years of returning. DRS Washington TRS Plan 1 page, Military service
- Out-of-state teaching. Vested Plan 2/3 members can use out-of-state teaching service credit (no cost, no limit) to qualify for early retirement or a smaller reduction; it is not used in the benefit. The Public Education Experience Program lets active members with at least two years of Plan 2/3 service buy up to seven years, which does count in the benefit (lump-sum payment, before retiring). Plan 1: out-of-state credit can be used to qualify for early retirement. DRS Washington TRS Plan 2 page, Using service credit earned outside Washington state; DRS Washington TRS Plan 1 page, Using out-of-state service credit to qualify for retirement
- Sick leave. Up to 45 days of unused sick leave (not cashed out) can become up to two months of service credit, used only to qualify for retirement, not in the benefit calculation. DRS Washington TRS Plan 1, 2 and 3 pages, Using sick leave to qualify for retirement
What the sources say
- When you retire you can buy 1 to 60 months of extra service credit. It raises your benefit by the plan formula but can't help you qualify. Example: a 65-year-old Plan 2 member with a $3,000 AFC buying 60 months adds $300 a month. At the application's illustrative factor that costs $42,981.DRS TRS23RAPP 11/2022, p. 12, Can I purchase additional service credit?
- Plan 2 and 3 members can use out-of-state teaching service to qualify for early retirement at no cost. They can also buy up to seven years through the Public Education Experience Program, which does raise the benefit.DRS Washington TRS Plan 2 page, Using service credit earned outside Washington state
- Military service that interrupted your Washington TRS job can often be credited, sometimes free. You must pay within five years of returning to work.DRS Washington TRS Plan 1 page, Military service
Questions
Can I buy service when I retire?
Yes. You can buy 1 to 60 whole months. It raises your pension by your plan's formula, but it can't help you qualify to retire.
How much does it cost?
The monthly increase divided by DRS's factor for your age and plan. The application's example: $300 more a month costs $42,981 at its illustrative factor. With the 2026 factor for age 65 it would be about $55,687.
What about military service?
Service that interrupted your job can often be credited, sometimes free. Otherwise you must pay within five years of returning.
Can out-of-state teaching count?
Plan 2 and 3 members who are vested can use it, free, to qualify for early retirement or a smaller reduction. To raise the pension, you'd buy it through the Public Education Experience Program.
Source: DRS plan pages for Washington TRS Plan 1, Plan 2 and Plan 3 (the DRS member handbook is now published as these web pages), retrieved Nov. 11, 2026, DRS plan pages (Plan 1, Plan 2, Plan 3); TRS23RAPP (11/2022) p. 12; DRS administrative factors 2026; RCW 41.32.064, 41.32.066. Last reviewed .