Montana MPERA Retirement Calculator
Estimate your Montana Public Employees’ Retirement System pension under the Defined Benefit Retirement Plan. Pick your hire date, enter your service and highest average compensation, and see what MPERA would pay.
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The formula
Monthly benefit = Retirement factor x Years of service credit x HAC
HAC, highest average compensation, is your highest 36 consecutive months of pay if you were hired before July 1, 2011, and your highest 60 consecutive months if you were hired after. For hires on or after July 1, 2013, any year counted is capped at 110% of the year before.
- Hired before July 1, 2011: 1.7857% with under 25 years, 2% with 25 or more.
- Hired on or after July 1, 2011: 1.5% with under 10 years, 1.7857% with 10 to 29, 2% with 30 or more.
The factor covers all of your service once you cross the line, so year 25 (or year 30) bumps everything. MPERA's handbook example: Wanda retires at 65 with 18 years and a $1,750 HAC. 1.7857% x 18 x $1,750 = $562.50 a month.
When you can retire
Hired before July 1, 2011, you can take a service retirement at 60 with 5 years, at 65 while still employed, or at any age with 30 years. There's no Rule of 80. Early retirement is open at 50 with 5 years or with 25 years at any age.
Hired on or after July 1, 2011, service retirement comes at 65 with 5 years or at 70 in active service. Early retirement opens at 55 with 5 years.
Early retirement is reduced by an early retirement factor. For pre-2011 hires it depends on how long until you'd reach 60 or 30 years; for later hires, how long until 65. MPERA doesn't publish the factors in the handbook, so this calculator shows the benefit before the reduction. Ask MPERA for an estimate before you decide.
The GABA compounds
Every January, MPERA raises the benefit that was paid the previous January (MCA 19-3-1605), once you've been retired 12 months. Because it builds on last year's amount, it compounds. Hired before July 1, 2007: 3%. Hired July 1, 2007 through June 30, 2013: 1.5%. Hired after: 1.5% minus 0.1% for every 2% the plan is below 90% funded, and 0% if the amortization period hits 40 years.
A $2,000 benefit with a 3% GABA is $2,688 after 10 increases. At 1.5% it's $2,321.
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Frequently asked questions
How is a Montana PERS pension calculated?
Retirement factor x years of service credit x highest average compensation (HAC). Hired before July 1, 2011: 1.7857% with under 25 years, 2% with 25 or more, on a 36-month HAC. Hired after: 1.5% with under 10 years, 1.7857% with 10 to 29, 2% with 30 or more, on a 60-month HAC. MPERA's example: 1.7857% x 18 years x $1,750 = $562.50 a month.
Does Montana PERS have a Rule of 80?
No. Members hired before July 1, 2011 retire unreduced at 60 with 5 years, at 65 while employed, or with 30 years at any age. Members hired after retire unreduced at 65 with 5 years or at 70 in active service.
Can I retire early?
Yes. Hired before July 1, 2011: at 50 with 5 years, or with 25 years at any age. Hired after: at 55 with 5 years. MPERA applies an early retirement factor based on how far you are from age 60 or 30 years (pre-2011) or from 65 (post-2011). MPERA does not publish the factors; ask for an estimate.
What is the GABA?
The Guaranteed Annual Benefit Adjustment. It is 3% if you were hired before July 1, 2007, 1.5% if hired July 1, 2007 through June 30, 2013, and 0% to 1.5% if hired after, depending on funding. It starts the January after 12 months of payments and compounds, because each increase applies to the benefit paid the previous January.
When am I vested?
After 5 years of membership service.