Idaho PERSI Calculator: How to Use It
PERSI's formula is short. The part that trips people up is the early reduction, which counts years to 65 or points to 90, whichever helps you more.
What this calculator does
It projects your service to your planned retirement age and computes 2% x service x your 42-month average salary. Then it checks your age: 65 or older is unreduced, 55 or older with 90 points is unreduced, 55 or older otherwise gets the statutory reduction. Before 55 with 5 years, you're vested and the benefit waits: unreduced at 65, or from 55 once your age plus service reaches 90.
The result is the regular (single life) allowance, before any survivor option.
What each input means
Current age and years of PERSI service
Use the credited service on your PERSI statement. The calculator adds a year for every year until your planned retirement.
Average salary, highest 42 months
Enter it as a yearly figure. PERSI uses your highest 42 consecutive months of gross salary.
Planned retirement age
The age you stop working and start the pension. It sets your points total and your years from 65.
Understanding the outputs
Green means unreduced, or vested with the full benefit starting at the age shown. Yellow means early, with the exact reduction. The points box shows age plus service so you can see how close you are to 90.
The COLA box assumes 1% a year, compounded. That's the automatic floor when inflation is at least 1%.
Years or points: a worked example
Kathy, from PERSI's own example, is 60 with 28 years. She's 5 years from 65 (15%) but only 2 points from 90 (6%). PERSI uses 6%. If she works one more year she reaches 61 + 29 = 90 and gets no reduction at all.
Related calculators
Frequently asked questions
What salary should I enter?
Your average gross salary over your highest 42 consecutive months, as an annual amount. Your annual statement and PERSI estimates show it.
How does the calculator decide if I meet the Rule of 90?
It adds your age and service at your planned retirement date. At 55 or older with 90 or more, you're unreduced. PERSI counts both in years and months, so fractions matter.
How is the early reduction figured?
It takes the smaller of the years until 65 or the points short of 90, then applies 3% a year for the first five years and 5.75% a year after that, by the month. Eight years early is 32.25%.
What COLA does the calculator assume?
1% a year, the automatic adjustment when CPI rises at least 1%. Anything above that needs board and legislative approval.
What if I leave before 55?
With 60 months of service you stay vested. The full benefit starts at 65, or as early as 55 once your age plus service reaches 90. You can also apply for a reduced benefit from 55.