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Find your membership
From the date you joined SDRS: before July 1, 2017 you're a Foundation member, on or after it a Generational member.
Foundation Handbook (July 2024), p. 7, Participation & Eligibility; SDCL 3-12C-101(46), (51) - 2
Project your service
We add the time from today to your start date to the years you enter, a year of service per year of work, unless you tell us the years are already what you'll have when you start. You need 3 years of contributory service to be vested.
Foundation Handbook (July 2024), p. 8, Earning Credited Service & Service Purchases; Generational Handbook (July 2024), p. 8; Foundation Handbook (July 2024), p. 8, Vesting; Generational Handbook (July 2024), p. 8; SDCL 3-12C-112 - 3
Apply the formula
Foundation: 1.7% × final average compensation × years before July 1, 2008 plus 1.55% × years after; if you enter a Social Security amount, we also work the alternate formula and use the larger. If you don't enter your years before July 2008, we assume continuous service from the date you joined. Generational: 1.8% × final average compensation × years.
Foundation Handbook (July 2024), p. 11, Normal Retirement Benefits (formula graphics, see source/handbook-image-text.txt); SDCL 3-12C-1106; SDRS Actuarial Valuation (June 30, 2024), pp. 53-54; Generational Handbook (July 2024), p. 11, Normal Retirement Benefits (formula graphic, see source/handbook-image-text.txt); SDCL 3-12C-1204 - 4
Check for an early cut
Ages count from the first of your birth month. Foundation: unreduced at 65 or the Rule of 85 (from 55); otherwise from 55, 0.25% for each full month to the earlier of 65 and the Rule of 85 date, as state law says. We also show the handbook's reading (to 65). Generational: from 57, 5% a year, by full month, to 67.
SDCL 3-12C-702; Foundation Handbook (July 2024), p. 12, Special Early Retirement Benefits (Rule of 85), Requirements to Meet the Rule of 85; SDCL 3-12C-1110(1); SDCL 3-12C-1111 (1/4 of 1% for each full month to the earlier of normal retirement age or reduction age); SDRS Actuarial Valuation (June 30, 2024), p. 56; Foundation Handbook (July 2024), p. 12 (3% a year, prorated for partial years, before age 65); Generational Handbook (July 2024), p. 11, Early Retirement Benefits (5% a year, prorated for partial years, before 67); SDCL 3-12C-1207 (5% per full year, prorated for each additional full month); SDRS Actuarial Valuation (June 30, 2024), p. 56 (5/12 of 1% per full month) - 5
Add the options and dates
Foundation: the automatic 60% spouse amount. Generational: joint & survivor amounts only for the 15 age pairs SDRS publishes. Your full-benefit date, and your first COLA on the July 1 after 12 months of payments.
Foundation Handbook (July 2024), p. 16, If you die after retirement; SDCL 3-12C-1114; Generational Handbook (July 2024), p. 16, 60 Percent and 100 Percent Joint & Survivor Benefit Reduction Examples; Foundation Handbook (July 2024), p. 13, Cost-of-Living Adjustments; Generational Handbook (July 2024), p. 12; SDCL 3-12C-104, 3-12C-704
The steps are explained in plain English in the guides to Foundation or Generational, the formula, early retirement and payment options. Try them in the calculator.
What the calculator doesn't cover
- Your final average compensation. We use the number you enter; SDRS figures it from your employer's reports with the 105% cap. The formula page works the cap on the handbook's example.
- Level income option amounts, and joint & survivor amounts for ages SDRS doesn't publish.
- Future COLAs. The calculator shows an illustration at the latest rate; real COLAs follow inflation and SDRS's funding.
- The Variable Retirement Account, the contribution credit lump sum, disability retirement and the cost of buying service.
- Health insurance, Social Security benefits and taxes.
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 the worked examples in the SDRS handbooks, plus the edges of each rule (ages 55, 57, 65 and 67, the Rule of 85, 3 years, and the 2008 and 2017 dates). The tests run every time the site is built.
| Example | Source shows | Our engine |
|---|---|---|
| Foundation member: Normal retirement (standard formula), 30 years, $30,000Foundation Handbook (July 2024), p. 11, Normal Retirement Benefit Example | $14,535.00 | $14,535.00Match |
| Foundation member: Early retirement at 62, 18 years, $30,000Foundation Handbook (July 2024), p. 12, Early Retirement Benefit Example | $7,657.65 | $7,657.65Match |
| Generational member: Normal retirement at 67, 30 years, $30,000Generational Handbook (July 2024), p. 11, Normal Retirement Benefit Example | $16,200.00 | $16,200.00Match |
| Generational member: Early retirement at 62, 30 years, $30,000Generational Handbook (July 2024), p. 11, Early Retirement Benefit Example | $12,150.00 | $12,150.00Match |
| Final average compensation with the 105% cap (Foundation example)Foundation Handbook (July 2024), p. 10, FAC example table and Contribution Credit | $34,734 | $34,734Match |
| Final average compensation with the 105% cap (Generational example)Generational Handbook (July 2024), p. 10, FAC example table and Contribution Credit | $34,384 | $34,734Check with SDRS |
| Joint & survivor, member 57, spouse 52Generational Handbook (July 2024), p. 16, 60 Percent and 100 Percent Joint & Survivor Benefit Reduction Examples | $942.29 / $879.88 | $942.29 / $879.88Match |
| Joint & survivor, member 57, spouse 57Generational Handbook (July 2024), p. 16, 60 Percent and 100 Percent Joint & Survivor Benefit Reduction Examples | $942.59 / $907.84 | $942.59 / $907.84Match |
| Joint & survivor, member 57, spouse 62Generational Handbook (July 2024), p. 16, 60 Percent and 100 Percent Joint & Survivor Benefit Reduction Examples | $958.81 / $933.19 | $958.81 / $933.19Match |
The Generational handbook's cap example doesn't match the law's method, so our engine gets a different average for it. See the 105% cap.
Things to check with SDRS
The sources don't settle these points. Each is labelled "Check with SDRS" where it shows up on the site.
The Foundation handbook describes the early retirement cut as 3% a year before age 65. State law and SDRS's actuary stop the cut at the date you would meet the Rule of 85, if that comes first. For members a few years short of the Rule of 85 the law gives a much smaller cut. We show the law's figure and the handbook's figure side by side.
What would settle it: An SDRS benefit estimate for a Foundation member who retires a few years before meeting the Rule of 85 (for example age 58 with 25 years).
The Generational handbook's pay-cap example cuts raises that were under 5%, which the law does not do. We use the law's method (each year limited to 105% of the highest earlier year counted), which matches the corrected Foundation handbook.
What would settle it: A corrected Generational handbook or an SDRS statement of the method.
Foundation members earn 1.7% for service before July 1, 2008 and 1.55% after. If you don't enter your years before July 1, 2008, we assume you worked without a break from your membership date. Your SDRS statement shows the real split.
What would settle it: The member's Personal Benefits Statement or MySDRS service detail.
The Foundation alternate formula subtracts 80% of your primary Social Security benefit, but the sources don't say at what age that amount is measured. We use it only if you type in a monthly Social Security amount.
What would settle it: SDRS rules (ARSD 62:01) or an SDRS estimate showing both formulas.
SDRS doesn't publish how much higher the level income option pays before 62, or how much lower after, so we can't show those amounts.
What would settle it: SDRS level income factors or a sample estimate.
SDRS publishes joint & survivor amounts only for a $1,000 benefit at 15 pairs of ages. For any other ages we can't show the reduced amount.
What would settle it: SDRS joint & survivor factor tables or the actuarial equivalence basis.
State law counts your birthday as the first of your birth month for eligibility. The sources don't say whether that also applies to the age 59 1/2 rule for going back to work; we assume it does.
What would settle it: SDRS guidance on the reemployment exception.
None of the SDRS sources mentions health coverage or a health subsidy for retirees. Ask your school district what it offers.
What would settle it: An SDRS or employer statement on retiree health.
The newest SDRS handbooks we found are dated July 2024. State law has changed a little since (2025 and 2026). We use the handbooks plus the current law.
What would settle it: The current handbook links from the SDRS Publications page.
The Variable Retirement Account contribution is set each year by the SDRS Board, from 0% to 1.5% of pay. Our newest source (2024) says 1.5%. We don't use it in the calculator.
What would settle it: The June 30, 2025 valuation or a Board resolution.
Where sources disagreed
- The Foundation handbook says an early benefit is cut 3% a year before 65. State law (SDCL 3-12C-1111) and SDRS's actuary measure the cut, 0.25% a month, only up to the earlier of 65 or your Rule of 85 date. Retiring at 58 with 25 years: 6% under the law, 21% by the handbook's wording. The handbook says the law wins, so we use 6% and show both. Foundation Handbook (July 2024), pp. 5, 12; SDCL 3-12C-1110(1), 3-12C-1111; SDRS Actuarial Valuation (June 30, 2024), p. 56
- The two handbooks show the same pay but different results. The Foundation handbook (corrected October 2024) gets an average of $34,734; the Generational handbook gets $34,384 because it also trims two raises of only 3%. The law uses the same words for both groups and matches the Foundation example, so we use that method for everyone. Foundation Handbook (July 2024; Oct. 18, 2024 file), pp. 9-10; Generational Handbook (July 2024), pp. 9-10; Foundation Handbook Aug. 13, 2024 file, p. 10; SDCL 3-12C-1104, 3-12C-1202
- A June 2026 SDRS board slide says Foundation members use a three-year average. The handbook, a 2025 SDRS newsletter and the law all say five years (20 quarters) for anyone whose service ends after June 30, 2022. We use five years. SDRS Update (June 2026), slide 12; Foundation Handbook (July 2024), p. 9; SDCL 3-12C-1103
- The handbooks say you get your first COLA after a full fiscal year (July 1 to June 30) of payments with no SDRS job. The law as changed in 2025 says 12 consecutive months of payments before July 1. Both give the same first COLA for a July or August start; we use the 12-month test. Foundation Handbook (July 2024), p. 13; SDCL 3-12C-104
- The handbook and law say service 'before July 1, 2008' earns 1.7% and service 'after July 1, 2008' earns 1.55%; the actuary says 'after June 30, 2008'. We count everything from July 1, 2008 at 1.55%. Foundation Handbook (July 2024), p. 11; SDCL 3-12C-1106; SDRS Actuarial Valuation (June 30, 2024), pp. 53-54
- In the Generational joint & survivor examples, the 60% amount for a member of 57 with a spouse of 57 ($942.59) is only 30 cents above the amount with a spouse of 52 ($942.29). Every other row rises about $20 for each five years of spouse age. It may be a typo; we show it as printed. Generational Handbook (July 2024), p. 16
Sources
- Class A Handbook for Foundation Members Joining SDRS prior to July 1, 2017 July 2024 (file dated Oct. 18, 2024)
- Class A Handbook for Generational Members Joining SDRS on or after July 1, 2017 July 2024 (file dated Aug. 13, 2024)
- Class A Handbook for Foundation Members (earlier file of the same July 2024 edition) July 2024 (file dated Aug. 13, 2024)
- SDCL chapter 3-12C, South Dakota Retirement System sdlegislature.gov, saved Nov. 12, 2026 (source notes run through SL 2026, ch. 24)
- South Dakota Retirement System Actuarial Valuation as of June 30, 2024 June 30, 2024 (plan provisions as amended through the 2024 session)
- SDRS Update (board presentation) June 2026 file (cover still reads June 4, 2025; contents cover FY 2025 results and the July 2026 COLA)
- SDRS Update for the Executive Board of the Legislative Research Council Aug. 26, 2026
- Planning For Your Financial Future Starts Now (SDRS new-member newsletter, Foundation edition) Undated (PDF created Dec. 8, 2025)
Handbook pages are the printed page numbers. Valuation pages are the printed numbers; board report cites are slide numbers. Last reviewed Nov. 12, 2026.
Source: SDRS Class A Handbooks (Foundation and Generational members), July 2024, Foundation pp. 7-8, 10-13, 16; Generational pp. 8, 10-12, 16, 60. Also: SDRS Actuarial Valuation (June 30, 2024) pp. 53-54, 56; SDCL §§ 3-12C-101, 3-12C-104, 3-12C-112, 3-12C-702, 3-12C-704, 3-12C-1106, 3-12C-1110, 3-12C-1111, 3-12C-1114, 3-12C-1204, 3-12C-1207. Last reviewed .