Age factor × Years of service × Salary average = Option A benefit (+ RetirementPlus %, never more than 80%)
Ready for Retirement 2026, p. 35, Example: Tier 1What the age factor is
The age factor is how much of your salary average you earn for each year of service. MTRS writes it as a decimal: 0.020 means 2% a year. It depends on your age at your last birthday on the day you retire, and on your tier. It stops rising at 65 in Tier 1 and 67 in Tier 2. Ready for Retirement 2026, p. 8 and p. 34, Option A age factor table; p. 31, Appendix A; MTRS web page 'Retiring from the MTRS', FAQ 'What is my retirement benefit based on?'; M.G.L. c. 32, § 10(1)
The age factor table
| Your age | Tier 1 | Tier 2 under 30 yrs | Tier 2 30+ yrs |
|---|---|---|---|
| 50 | 0.010 | — | — |
| 51 | 0.011 | — | — |
| 52 | 0.012 | — | — |
| 53 | 0.013 | — | — |
| 54 | 0.014 | — | — |
| 55 | 0.015 | — | — |
| 56 | 0.016 | — | — |
| 57 | 0.017 | — | — |
| 58 | 0.018 | — | — |
| 59 | 0.019 | — | — |
| 60 | 0.020 | 0.0145 | 0.01625 |
| 61 | 0.021 | 0.016 | 0.0175 |
| 62 | 0.022 | 0.0175 | 0.01875 |
| 63 | 0.023 | 0.019 | 0.020 |
| 64 | 0.024 | 0.0205 | 0.02125 |
| 65 | 0.025 | 0.022 | 0.0225 |
| 66 | 0.025 | 0.0235 | 0.02375 |
| 67+ | 0.025 | 0.025 | 0.025 |
— means you can't retire at that age in that tier. Tier 1 continues below 50 for members with 20 years: Below 55 (only possible with 20+ years): the age-55 factor less 0.001 for each year the age at last birthday is under 55. Ready for Retirement 2026, p. 8 and p. 34, Option A age factor table; p. 31, Appendix A; MTRS web page 'Retiring from the MTRS', FAQ 'What is my retirement benefit based on?'; M.G.L. c. 32, § 10(1)
Age factors come from MTRS's booklet, which matches its separate Tier 1 and Tier 2 charts.
We use the age factors printed in MTRS's booklet (p. 34).
Ready for Retirement 2026, p. 34; M.G.L. c. 32, § 5(2)(a)We don't estimate a Tier 1 benefit before age 41.
We show no Tier 1 estimate before age 41.
Ready for Retirement 2026, p. 8; M.G.L. c. 32, § 10(1)Percentage of salary average, by age and service
Age factor × years, before RetirementPlus. Cells at 80% have hit the cap. MTRS prints the full charts for every year of service; every cell matches our engine (Tier 2's chart cuts to two decimals, for example 50.37 for 50.375).
| Age | 20 yrs | 25 yrs | 30 yrs | 35 yrs |
|---|---|---|---|---|
| 55 | 30% | 37.5% | 45% | 52.5% |
| 56 | 32% | 40% | 48% | 56% |
| 57 | 34% | 42.5% | 51% | 59.5% |
| 58 | 36% | 45% | 54% | 63% |
| 59 | 38% | 47.5% | 57% | 66.5% |
| 60 | 40% | 50% | 60% | 70% |
| 61 | 42% | 52.5% | 63% | 73.5% |
| 62 | 44% | 55% | 66% | 77% |
| 63 | 46% | 57.5% | 69% | 80% |
| 64 | 48% | 60% | 72% | 80% |
| 65+ | 50% | 62.5% | 75% | 80% |
| Age | 20 yrs | 25 yrs | 30 yrs | 35 yrs |
|---|---|---|---|---|
| 60 | 29% | 36.25% | 48.75% | 56.875% |
| 61 | 32% | 40% | 52.5% | 61.25% |
| 62 | 35% | 43.75% | 56.25% | 65.625% |
| 63 | 38% | 47.5% | 60% | 70% |
| 64 | 41% | 51.25% | 63.75% | 74.375% |
| 65 | 44% | 55% | 67.5% | 78.75% |
| 66 | 47% | 58.75% | 71.25% | 80% |
| 67+ | 50% | 62.5% | 75% | 80% |
The 80% cap
However many years you work, your Option A benefit can't be more than 80% of your salary average. That includes RetirementPlus. Ready for Retirement 2026, p. 7 (maximum allowance, 80%) and p. 35 (** may not exceed 80 percent); M.G.L. c. 32, § 5(2)(c)
MTRS's own example: a Tier 1 member at 58 with 35 years has 0.018 × 35 = 63%, plus 22% RetirementPlus = 85%. The cap brings it to 80%: 80% × $65,000 = $52,000 a year. Ready for Retirement 2026, p. 35, Example: Tier 1
Once you're at 80%, another year adds nothing unless your salary average goes up. Years of service it takes to reach the cap on the regular formula:
| Retiring at | Tier 1 | Tier 2 |
|---|---|---|
| 55 | 54 years | — |
| 58 | 45 years | — |
| 60 | 40 years | 50 years |
| 62 | 37 years | 43 years |
| 65 | 32 years | 36 years |
| 67 | 32 years | 32 years |
Our engine on MTRS's age factors. RetirementPlus gets you there sooner: see RetirementPlus.
Veterans: A military veteran (as defined in M.G.L. c. 32, § 1) gets $15 per year of creditable service added to the Option A allowance, up to $300 a year, even on top of the 80% maximum. Partial years round up (15.2 years = 16 x $15 = $240). Ready for Retirement 2026, p. 7, Veteran's benefit; M.G.L. c. 32, § 5(2)(b) ('each year of creditable service or fraction thereof')
Your age: last birthday, no rounding
- Your age factor uses your age at your last birthday on the retirement date; MTRS does not round up.MTRS web page 'Retiring from the MTRS', FAQ 'What is my retirement benefit based on?'; Ready for Retirement 2026 p. 8
If you are under 65 (Tier 1) or 67 (Tier 2), retiring on a summer birthday instead of June 30 gives a higher age factor for life; mid-year, working to the end of the month earns the full month of service. Ready for Retirement 2026, p. 38, Appendix D
Years of service: full months only
For the percentage of salary average, full years and full months of creditable service count. Example: a 10-month teacher retiring March 10 with 32 years, 6 months and 10 days (32.6549 years) is credited 32.6 years: the first decimal place is full months, and partial months are dropped. For the RetirementPlus increase only whole years count (32.9 years = 32 years). Ready for Retirement 2026, p. 32 and p. 33, '* Two notes on years of service'; M.G.L. c. 32, § 5(2)(a) ('years and full months')
So 32 years, 6 months and 10 days (32.6549 years) counts as 32.6.
We drop partial months. For 10-month contracts each month is 0.1 year, as in MTRS's example; for 12-month contracts we count months as twelfths.
We count a 10-month contract year in tenths, as MTRS's example does, and a 12-month contract year in twelfths, dropping partial months.
Ready for Retirement 2026, p. 32Part-time service is prorated, and then MTRS uses your full-time-equivalent salary. MTRS's example, Molly Music: age 60 (0.020) × 24.5 years = 49% × $74,000 = $36,260 a year. Ready for Retirement 2026, p. 39, Appendix E
Salary average
- Tier 1: the average of your three highest consecutive years' regular compensation, or your last three years, whichever is greater. Tier 2: the same with five years.MTRS web page 'Retiring from the MTRS'; M.G.L. c. 32, § 5(2)(a)
- Check with MTRSA year's pay counts only up to 10% more than the average of the two years before it. The law lists exceptions, such as more hours, a real change in position, or collectively bargained raises.The booklet states the 10% rule only for Tier 1. The statute isn't limited by tier.Ready for Retirement 2026 p. 7; M.G.L. c. 32, § 5(2)(f)
- Tier 2: if your pay in any two consecutive years of your last five differs by more than 100%, your benefit uses the average of your last five years.M.G.L. c. 32, § 5(2)(a)
- Only 'regular compensation' counts. Payments made because your employer knew you were retiring, and payments in lieu of sick leave or vacation, are excluded. For 2026, pensionable pay is capped at $360,000 for members after 1995 and $230,400 for members after January 1, 2011.Ready for Retirement 2026 p. 3 and p. 14
In the salary-history helper we cap each year's counted pay at 110% of the average of the two years before it, for both tiers; exceptions in the law (more hours, promotions, bargained raises) aren't modelled.
The calculator uses the salary average you enter, so this matters only if you work out your average yourself.
Ready for Retirement 2026, p. 7; M.G.L. c. 32, § 5(2)(f)Try your own numbers in the calculator, or see what one more year adds.
Questions
What is the MTRS age factor?
The share of your salary average you earn for each year of service, based on your age at your last birthday on your retirement date. Tier 1 goes from 0.015 at 55 to 0.025 at 65. Tier 2 goes from 0.0145 at 60 to 0.025 at 67, with a higher table for members with 30 years.
What is the 80% cap?
Your benefit can't be more than 80% of your salary average, even with RetirementPlus. A veteran's benefit is the only thing added on top.
Does MTRS round my age up?
No. MTRS uses your age at your last birthday on your retirement date.
Source: MTRS Ready for Retirement reference guide, 2026, pp. 3, 7, 8, 14, 31, 32, 32-34, 33, 34, 35, 38, 39. Also: MTRS web page 'Retiring from the MTRS'; M.G.L. c. 32, §§ 5, 10. Last reviewed .