South Dakota SDRS Retirement Calculator: How to Use It
SDRS has two Class A designs. Foundation members joined before July 1, 2017 and can use the Rule of 85. Generational members joined after, earn 1.8% a year and retire unreduced at 67.
What this calculator does
It estimates the single-life Class A benefit using the standard formula from the SDRS handbooks (July 2024). It projects service to your planned retirement age, then decides whether that's normal retirement, Rule of 85 (Foundation only), reduced early retirement, a deferred benefit, or not vested. Class B members, survivor options, the Foundation alternate formula, the level income option and the Generational Variable Retirement Account aren't modeled. MySDRS has the official estimator.
What each input means
Membership group
Foundation if you joined before July 1, 2017. Generational if you joined on or after it.
Years of service so far
SDRS credits one quarter of a year for each calendar quarter you contribute. Include service you've already purchased. The calculator adds the years between now and your retirement age.
Service before July 1, 2008 (Foundation)
Those years earn 1.7%. Later years earn 1.55%.
Final average compensation
Your highest 20 consecutive quarters out of your last 40, with each year capped at 105% of the year before.
Planned retirement age
The age you stop SDRS-covered work and start benefits. If you leave before the earliest retirement age (55 or 57) with at least 3 years, the calculator shows the unreduced benefit at the earliest age you could take it.
Understanding the outputs
Foundation, 25 years (10 before July 2008), $60,000 FAC, retiring at 60: 60 + 25 = 85, so no reduction. The benefit is 1.7% x $60,000 x 10 + 1.55% x $60,000 x 15 = $10,200 + $13,950 = $24,150 a year. Leave the same member at 58 with 23 years and 58 + 23 = 81, so it's early retirement at 3% x 7 = 21% off.
Generational, 30 years, $60,000 FAC: $32,400 a year at 67. At 62 it's 25% less, $24,300.
The COLA panel shows the 0% floor next to the July 2026 rate of 1.56% repeated each year. The real COLA changes every year.
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Frequently asked questions
Am I a Foundation or Generational member?
Foundation if you joined SDRS before July 1, 2017. Generational if you joined on or after that date, or if you took a refund and rejoined after it. Your annual Personal Benefits Statement and MySDRS show which.
Why does the calculator ask for service before July 1, 2008?
Foundation members earn 1.7% of FAC for each year before July 1, 2008 and 1.55% for each year after. Generational members earn 1.8% on everything, so the question doesn't apply to them.
How does the Rule of 85 work?
Foundation members can retire unreduced once age plus credited service reaches 85, as long as they're at least 55. Generational members have no Rule of 85.
Does SDRS have a COLA?
Yes, set each July by the SDRS board between 0% and 3.5%, based on CPI-W and the funded ratio. It was 1.56% for July 1, 2026. The first one comes after a full July-to-June year of benefits.
Does SDRS coordinate with Social Security?
SDRS members are also covered by Social Security. A Foundation member retiring between 55 and 62 can choose the level income option, which pays more from SDRS before 62 and less after, so SDRS plus Social Security stays roughly level.