This page explains the MTRS calculator. The rules it uses are in plain English on the age factor, RetirementPlus and payment options pages.
- 1
Find your tier
From your membership date: Tier 1 before April 2, 2012, Tier 2 on or after. You tell us whether you're in RetirementPlus; if you're not sure, we assume yes for members who joined on or after July 1, 2001 (when it became required).
Ready for Retirement 2026, p. 31, Appendix A; M.G.L. c. 32, § 5(1)(a); M.G.L. c. 32, § 5(4)(i); Ready for Retirement 2026, p. 6, p. 32, p. 33; MTRS web page 'RetirementPlus (R+) election change chart'; MTRS web page 'Contribution rates explained' - 2
Project your service
We add the time from today to your retirement date to the service you enter, a month of credit per month, then drop partial months: on a 10-month contract each month is 0.1 year. The work-longer comparison adds a year of service for each year.
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') - 3
Check eligibility
Tier 1: 20 years at any age, or 55 with 10 (55 with no minimum if you joined before 1978). Tier 2: 60 with 10.
Ready for Retirement 2026, p. 31, Appendix A, and p. 32, Appendix B; M.G.L. c. 32, §§ 5(1)(a), 10(1); Ready for Retirement 2026, p. 31, Appendix A, and p. 33, Appendix B; M.G.L. c. 32, § 5(1)(a) - 4
Look up your age factor
Your age at your last birthday on your retirement date, in your tier's table. Tier 2 members with 30 or more years use the higher table.
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); Ready for Retirement 2026, p. 34, Option A age factor table; p. 31, Appendix A; M.G.L. c. 32, § 5(2)(a) (second table: members on or after April 2, 2012 with at least 30 years) - 5
Apply the formula
Age factor × service, plus 2% for each full year over 24 (Tier 1) or 23 (Tier 2) if you qualify for RetirementPlus, capped at 80%, × your salary average. Then the veteran's benefit, if any.
Ready for Retirement 2026, p. 6, p. 7 (RetirementPlus percentage table for Tier 1 members), p. 31, p. 32; M.G.L. c. 32, § 5(4)(ii); 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); 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') - 6
Add options and dates
Option B as a range, Option C from PERAC's factor table at each person's closer age, the date your age factor tops out (or you reach the cap), and your first COLA date.
Ready for Retirement 2026, p. 8 and p. 36, Determining your and your beneficiary's closer ages; p. 37, Option C factor table (ages 50-72 x 50-75; ages 21-90 on PERAC's site); MTRS web page 'Your benefit payment', Cost-of-living adjustments; MTRS news (July 13, 2026); Ready for Retirement 2026, p. 30 and p. 38, Appendix D; M.G.L. c. 32, § 102(a), (c)
What the calculator doesn't cover
- Your salary average. We use the number you enter; MTRS figures it from your records, including the 10% limit on raises and the pensionable earnings limits.
- Exact Option B amounts. MTRS publishes no Option B factors.
- Disability and termination retirement, and the member-survivor benefit in the calculator (it's worked on the survivor benefits page).
- Whether you meet RetirementPlus's 20-year teaching and five-year 11% rules. We take your word for it.
- Retiree health insurance, which your district provides, and income tax.
- Future COLAs, which the Legislature votes each year.
- The Boston Retirement System and the other Massachusetts retirement systems.
How we check the math
The calculator runs on a small engine that reads every rule from one data file, with a source for each. Automated tests check it against every worked example MTRS publishes and every cell of MTRS's Tier 1 and Tier 2 retirement-percentage charts, plus the edges of each rule (the April 2, 2012 tier date, each eligibility rule, the 30-year RetirementPlus line, the 80% cap, closer ages, COLA dates). The tests run every time the site is built. MTRS's worksheet rounds to whole dollars, so we allow $1.
| Example | MTRS shows | Our engine |
|---|---|---|
| Worksheet Tier 1, 35 years: Option AReady for Retirement 2026, p. 35, Example: Tier 1 | $52,000 | $52,000Match |
| … final Option A with veteran's benefitReady for Retirement 2026, p. 35, Example: Tier 1 | $52,300 | $52,300Match |
| … Option C (factor 0.9194)Ready for Retirement 2026, p. 35, Example: Tier 1 | $48,109 | $48,109Match |
| … Option C survivorReady for Retirement 2026, p. 35, Example: Tier 1 | $32,073 | $32,073Match |
| Worksheet Tier 2, 28 years: Option AReady for Retirement 2026, p. 35, Examples: Tier 2, with less than 30 years | $24,360 | $24,360Match |
| … final Option A with veteran's benefitReady for Retirement 2026, p. 35, Examples: Tier 2, with less than 30 years | $24,660 | $24,660Match |
| … Option C (factor 0.9099)Ready for Retirement 2026, p. 35, Examples: Tier 2, with less than 30 years | $22,465 | $22,465Match |
| … Option C survivorReady for Retirement 2026, p. 35, Examples: Tier 2, with less than 30 years | $14,977 | $14,977Match |
| Worksheet Tier 2, 30 years: Option AReady for Retirement 2026, p. 35, Examples: Tier 2, with 30 years or more | $39,533 | $39,533Match |
| … final Option A with veteran's benefitReady for Retirement 2026, p. 35, Examples: Tier 2, with 30 years or more | $39,833 | $39,833Match |
| … Option C (factor 0.9099)Ready for Retirement 2026, p. 35, Examples: Tier 2, with 30 years or more | $36,271 | $36,271Match |
| … Option C survivorReady for Retirement 2026, p. 35, Examples: Tier 2, with 30 years or more | $24,181 | $24,180Match |
| Molly Music, part-time, 24.5 years at 60Ready for Retirement 2026, p. 39, Appendix E | $36,260 | $36,260Match |
| Service: 32.6549 years on a 10-month contractReady 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') | 32.6 | 32.6Match |
| Death in service at 42, 20 years (a month)MTRS web page 'Survivor benefits for active members'; Ready for Retirement 2026, p. 31 (Active death benefit formula); M.G.L. c. 32, §§ 12(2)(d), 12B | $976 | $976Match |
| COLA: $40,000 after three COLAsMTRS web page 'Your benefit payment', Cost-of-living adjustments; MTRS news (July 13, 2026); Ready for Retirement 2026, p. 30 and p. 38, Appendix D; M.G.L. c. 32, § 102(a), (c) | $41,170 | $41,170Match |
| Working after retirement: Trudy Teacher's 2026 limitMTRS web page 'Working after retirement'; Ready for Retirement 2026, pp. 27-28; PERAC Memo 21/2026, pp. 1-2; M.G.L. c. 32, § 91(b) as amended by FY2027 budget § 30 | $17,000 | $17,000Match |
| Working after retirement: Trudy Teacher's 2027 limitMTRS web page 'Working after retirement'; Ready for Retirement 2026, pp. 27-28; PERAC Memo 21/2026, pp. 1-2; M.G.L. c. 32, § 91(b) as amended by FY2027 budget § 30 | $17,000 | $17,000Match |
| Working after retirement: Trudy Teacher's 2028 limitMTRS web page 'Working after retirement'; Ready for Retirement 2026, pp. 27-28; PERAC Memo 21/2026, pp. 1-2; M.G.L. c. 32, § 91(b) as amended by FY2027 budget § 30 | $42,000 | $42,000Match |
| Retirement percentage chart: Tier 1, regular and RetirementPlusReady for Retirement 2026, p. 32, Appendix B | 546 of 546 cells | 546 of 546Match |
| Retirement percentage chart: Tier 2, regular and RetirementPlusReady for Retirement 2026, p. 33, Appendix B | 256 of 256 cells | 256 of 256Match |
Things to check with MTRS
The sources don't settle these points. Each is labeled "Check with MTRS" where it shows up on the site.
How full months convert to decimal service for 12-month employees. The only worked example (p. 32) is a 10-month teacher, where the first decimal place is months (32 years 6 months = 32.6). For a 12-month employee a month is 1/12 of a year.
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. 32Option C 'closer age' when the retirement date is exactly halfway between birthdays. The booklet explains closer age by counting months and days but gives no tie rule.
If the retirement date is exactly midway between two birthdays, we use the lower age. On an exact tie we use the lower age.
Ready for Retirement 2026, p. 36Tier 1 age factor below age 41. The age factor table starts at 41 (0.001). The § 10(1) rule (0.001 less per year under 55) would give 0 at age 40.
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)Whether the 10% salary-increase limit applies to Tier 2 salary averages. The booklet mentions it only for Tier 1; the statute § 5(2)(f) is not limited by tier.
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)Age factor tables in M.G.L. c. 32, § 5(2)(a). The tables on malegislature.gov are images (32-5-1.bmp to 32-5-3.bmp) that returned 404, so the statute tables could not be checked against the booklet.
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)Exact Option B reduction. MTRS publishes no Option B factors, only 'approximately 1-3% less' (more at 75+), and illustrates with 2%.
Option B is shown as a range (1% to 3% less than Option A) plus MTRS's 2% illustration. We show Option B as 1% to 3% less than Option A, plus MTRS's own 2% illustration.
Ready for Retirement 2026, p. 6 and p. 35Future COLAs. COLAs are voted each year by the Legislature (lesser of CPI or 3%, on the first $13,000) and are not guaranteed; the base has been $13,000 since November 2011. The enhanced COLA and base increases in the FY2027 budget wait on the new COLA Reserve Fund.
Our COLA projection assumes 3% on the first $13,000 every year, the amount granted in most recent years. It is an assumption, not a promise. Our projection assumes 3% of the first $13,000 each year.
MTRS web page 'Your benefit payment', Cost-of-living adjustments; MTRS news (July 13, 2026)RetirementPlus 20-year teaching requirement and 5-year 11% contribution requirement. The estimator can't see your membership-service history or contribution record.
If you say you're in RetirementPlus and have 30+ years, we assume at least 20 are MTRS/Boston teaching service and that you have (or will pay for) five years at 11%, unless you enter fewer teaching years. We assume you meet both unless you enter fewer teaching years.
Ready for Retirement 2026, p. 12 and p. 32; M.G.L. c. 32, § 5(4)(i)-(ii)Which membership date triggers the $230,400 (2026) cap. The booklet's sentence is cut off ('the maximum amount of regular compensation for a member whose most recent date $230,400 in 2026'); its heading says 'After 1/1/2011'.
We flag salary averages over $230,400 for members who joined after Jan. 1, 2011 and over $360,000 for members after 1995. We show a note above $230,400 for members who joined after Jan. 1, 2011, and above $360,000 for members who joined after 1995.
Ready for Retirement 2026, p. 3Retiree health premium share. Retiree health is a local district benefit; MTRS publishes no premium shares.
We can't estimate your retiree health cost; ask your district. Not estimated: ask your district.
Ready for Retirement 2026, p. 9; MTRS web page 'Health insurance'Termination retirement and disability benefit amounts. Termination retirement needs the annuity value of your account; disability formulas need data the sources don't give in full.
The estimator covers superannuation (regular and RetirementPlus) only. Not estimated: the calculator covers regular and RetirementPlus retirement only.
MTRS web page 'Retiring from the MTRS'; Ready for Retirement 2026, p. 31Where sources disagreed
- Working after retirement: extra earnings after one full calendar year. Ready for Retirement 2026 p. 28 and the MTRS 'Working after retirement' page: $25,000 after one full calendar year of retirement. M.G.L. c. 32, § 91(b) as shown on malegislature.gov (Nov. 11, 2026) still reads '$15,000'. What we do: $25,000 (MTRS and PERAC, calendar year 2026 on) PERAC Memo 21/2026 quotes FY2027 budget § 30 striking '$15,000' and inserting '$25,000' (signed July 9, 2026; applies to all of calendar year 2026). The website text is simply not yet updated.
- Working after retirement: when the extra amount starts. Ready for Retirement 2026 p. 28: 'After the member has been retired for at least one full calendar year (one full January-through-December year)'. M.G.L. c. 32, § 91(b) text: 'in the first 12 months immediately following the effective date of retirement' the extra amount does not apply. What we do: After one full January-December calendar year of retirement (MTRS table: retire in 2026 -> Jan. 1, 2028). PERAC Memo 21/2026 p. 1 also says § 91 'still requires that an individual be retired for a full calendar year'. Follow MTRS/PERAC.
- Working after retirement worked example (COLA variant). The formula on the same page and the non-COLA example ($42,000 for 2028 = $17,000 + $25,000). MTRS 'Working after retirement' page footnote *** says 2028 allowable earnings 'would decrease by $585, to $31,415' - which is $65,000 - $48,585 + $15,000, i.e. the old $15,000 figure. What we do: Formula: $65,000 - $48,585 + $25,000 = $41,415 for 2028. Test the formula; the footnote looks left over from the $15,000 limit.
- Pensionable earnings limit year. Ready for Retirement 2026 p. 3: 'the pensionable earnings limit for calendar year 2026 is $360,000'. Same page, next paragraph: 'In 2025, the 401(a)(17) limit is $360,000' (then '$230,400 in 2026 (64% of $360,000)'). What we do: $360,000 for calendar year 2026. Treated as a typo for 2026.
- Tier 2 retirement percentage chart rounding. Ready for Retirement 2026 p. 33 prints 50.37, 58.12, 53.62 ... (truncated to two decimals). Age factor table p. 34 and M.G.L. c. 32, § 5(2)(a) (factor x years). What we do: Exact products (0.01625 x 31 = 50.375%). The chart is a display rounding; tests check each printed cell equals the exact value truncated to two decimals.
- Veteran's benefit: which years count. Ready for Retirement 2026 p. 7: '$15 per year of creditable service'; M.G.L. c. 32, § 5(2)(b): 'each year of creditable service or fraction thereof'. Ready for Retirement 2026 p. 35 footnote *** and the MTRS survivor page: 'If you are a wartime veteran, $15 for each year of teaching service'. What we do: $15 per year of creditable service (partial years rounded up), max $300. Follow p. 7 and the statute; the footnote is shorthand.
- 10% limit on salary increases in the salary-average years. Ready for Retirement 2026 p. 7 states the 10% rule in the Tier 1 bullet only. M.G.L. c. 32, § 5(2)(f) applies to 'regular compensation in any year' for all members, with exceptions (more hours, overtime, bona fide position change, collectively bargained schedules, etc.). What we do: Applied to both tiers (statute has no tier limit), with the statutory exceptions not modelled. Engine's fasFromSalaries applies it to both tiers; see needsValidation `anti-spiking-tier2`.
- Rounding in the benefit estimate worksheet. Ready for Retirement 2026 p. 35 rounds most lines to whole dollars ($47,808.80 -> $47,809; $39,532.50 -> $39,533). Same page: Option B $24,360 x 98% = $23,872.80 printed as $23,872 (truncated). What we do: Engine keeps cents; tests allow $1. Display rounding only.
Sources
- MTRS Ready for Retirement reference guide 2026 (print code 0926; sample application Form RAP-10082026)
- PERAC Option C Factor Table, for retirements on or after December 27, 2004 (member and beneficiary ages 21-90) as posted by MTRS (file dated 2018/01)
- MTRS Retirement percentage chart, Membership Tier 1 as posted by MTRS (file dated 2018/02)
- MTRS Retirement percentage chart, Membership Tier 2 as posted by MTRS (file dated 2018/03)
- MTRS Beneficiary Designation Form for Retirees and Survivors Form RBD-11202023
- Introduction to the MTRS (employer training slides) Spring 2026
- PERAC Memo 21/2026: Updated Calculation Figures for Post-Retirement Work Under Section 91 and Section 91A July 13, 2026
- MTRS web page: Membership Tier 1 vs. Tier 2 retrieved Nov. 11, 2026
- MTRS web page: Retiring from the MTRS retrieved Nov. 11, 2026
- MTRS web page: Your benefit payment (cost-of-living adjustments, COLA history) retrieved Nov. 11, 2026
- MTRS news: FY2027 State Budget Includes COLA, Future COLA Enhancements & Higher Post-Retirement Earnings Limit posted July 13, 2026
- MTRS web page: Working after retirement retrieved Nov. 11, 2026
- MTRS web page: Leaving MTRS service prior to retirement retrieved Nov. 11, 2026
- MTRS web page: Survivor benefits for active members retrieved Nov. 11, 2026
- MTRS web page: Benefits for survivors of retirees retrieved Nov. 11, 2026
- MTRS web page: Social Security retrieved Nov. 11, 2026
- MTRS web page: Taxation of your benefit retrieved Nov. 11, 2026
- MTRS web page: Health insurance retrieved Nov. 11, 2026
- MTRS web page: Contribution rates explained retrieved Nov. 11, 2026
- MTRS web page: RetirementPlus (R+) election change chart retrieved Nov. 11, 2026
- MTRS web page: Annuity savings account retrieved Nov. 11, 2026
- MTRS web page: Plan summary retrieved Nov. 11, 2026
- M.G.L. c. 32, § 5 (Superannuation retirement; § 5(4) RetirementPlus) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 10 (Superannuation and termination retirement after leaving service) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 11 (Return of accumulated deductions) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 12 (Method of payment: Options A, B, C, D) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 12B (Survivor allowances) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 22 (Contributions) malegislature.gov, retrieved Nov. 11, 2026
- M.G.L. c. 32, § 91 (Employment of retirees) malegislature.gov, retrieved Nov. 11, 2026 (text not yet updated for FY2027 budget § 30)
- M.G.L. c. 32, § 102 (Cost-of-living adjustments, state and teachers' systems) malegislature.gov, retrieved Nov. 11, 2026
We cite the page number printed on each page of the Ready for Retirement guide. The age factor tables in M.G.L. c. 32, § 5(2)(a) are images on malegislature.gov that we couldn't retrieve, so the age factors come from MTRS's guide; its Tier 1 and Tier 2 charts agree with them. Last reviewed Nov. 12, 2026.
Source: MTRS Ready for Retirement reference guide, 2026, pp. 3, 6, 7, 8, 9, 12, 27-28, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39. Also: MTRS web pages 'RetirementPlus (R+) election change chart', 'Contribution rates explained', 'Retiring from the MTRS', 'Your benefit payment', 'Health insurance', 'Survivor benefits for active members', 'Working after retirement'; MTRS news (July 13, 2026); PERAC Memo 21/2026 pp. 1-2; M.G.L. c. 32, §§ 5, 10, 12, 12B, 91, 102. Last reviewed .