The facts
- Each extra year adds 1/60 of your AFC to your yearly benefit. For Tier Two, reaching 60 with 30 years moves you to 1.85% for every year.MCA 19-20-801, 19-20-804
- Working until you're eligible for full benefits removes the early-retirement reduction: 60, or 25 years (Tier One); 60, or 55 with 30 years (Tier Two).MCA 19-20-801, 19-20-802
- A full-time year is at least 180 days in a fiscal year, at least 140 hours a month for at least 9 months, or at least 1,080 hours under an alternative school calendar. Part-time service is credited in proportion to full-time.Montana TRS web page: Glossary of Terms (full-time service; part-time service)
- Check with Montana TRSYour benefit is based on your years of service and your AFC, not on your account balance, so an extra year raises it even though your contributions earn only interest.Montana TRS says your benefit is based on service and AFC, not your account balance; the page doesn't itself say how much an extra year adds. Check with Montana TRS.Montana TRS web page: Saving for Your Future
Two examples
Our engine on Montana TRS's rules, on a $60,000 AFC with no raises. Early rows show the amount before the reduction, because Montana TRS doesn't publish its factors. Check with Montana TRS
Tier One: 57 with 22 years
| Retire | Years | Monthly |
|---|---|---|
| Jul 1, 2027age 57 | 22 | $1,833before the cut |
| Jul 1, 2028age 58 | 23 | $1,917before the cut |
| Jul 1, 2029age 59 | 24 | $2,000before the cut |
| Jul 1, 2030age 60 | 25 | $2,083full benefit |
At 25 years the reduction ends at any age. Load it in the calculator
Tier Two: 58 with 28 years
| Retire | Years | Monthly |
|---|---|---|
| Jul 1, 2041age 58 | 28 | $2,333before the cut |
| Jul 1, 2042age 59 | 29 | $2,417before the cut |
| Jul 1, 2043age 60 | 30 | $2,775full, at 1.85% |
At 60 with 30 years every year counts at 1.85%. Load it in the calculator
In the Tier Two example, the jump from 29 to 30 years at 60 adds $358 a month before counting the end of the reduction: 1/60 becomes 1.85% on every year. MCA 19-20-101(34), 19-20-801(2)-(3), 19-20-802(1)(b), 19-20-804, 19-20-805(1)(b); Montana TRS web page: Understand Your Benefits (Tier 2 Service Retirement; Tier 2 Professional Option); Actuarial Valuation (July 1, 2025), pp. 47-48, Appendix B; Montana TRS FY2025 ACFR, p. 19 (Summary of Benefits)
MCA 19-20-802(3) requires actuarially equivalent factors from the latest valuation; no source publishes them. The valuation describes only the reduction period (lesser of years to 60 or years to 25/30 of service).
Unreduced amount shown, reduction period computed, reduced amount left blank
What would settle it: Montana TRS's current factor table or an Estimate of Benefits for an early retiree.
See your own numbers in the calculator, which compares retiring as planned with 1, 2 and 3 more years. How the reduction period is set: early retirement.
Questions
How much does one more year add to a Montana TRS pension?
1/60 of your AFC a year: $83.33 a month on a $60,000 AFC. More if you get a raise, and more again if it ends an early-retirement reduction.
Why can the last year before 60 be worth so much?
It can end the early-retirement reduction, which otherwise lasts for life. In Tier Two, reaching 60 with 30 years also moves every year of service from 1/60 to 1.85%.
Source: Montana TRS: Understand Your Benefits (web page) and fact sheets, Fetched Nov. 12, 2026; fact sheets revised 2019-2026. Also: Montana TRS web pages: Glossary of Terms, Saving for Your Future; Actuarial Valuation (July 1, 2025); FY2025 Annual Comprehensive Financial Report; MCA §§ 19-20-101, 19-20-703, 19-20-801, 19-20-802, 19-20-804, 19-20-805. Last reviewed .