PERS uses three methods to calculate a Tier One monthly pension benefit amount and two methods to calculate a
Tier Two monthly pension benefit amount. The calculation methods are:
-
Tier One — Full Formula, Formula Plus Annuity (only for eligible Tier One members) and
Money Match
-
Tier Two — Full Formula and Money Match
The equations for these calculation methods are shown below, but your monthly pension benefit may not be
determined by these equations alone.
At retirement, you can choose among several survivorship or nonsurvivorship benefit options. With these options,
you decide whether and how a benefit may be paid to a beneficiary upon your death.
The option you choose at retirement will affect your monthly benefit amount. The equations
below show the calculation for the “Refund Annuity” option. If you choose a different option at retirement, your
benefit calculation will include additional adjustments based on factors such as your estimated lifespan and the
estimated lifespan of your beneficiary.
Read more about survivorship and nonsurvivorship options in our
Tier One/Tier Two and
Individual Account Program (IAP) Preretirement Guide.
Here are the equations that PERS starts with:
Full Formula
(Tier One and Tier Two)
Your years of service are multiplied by your final average salary and a set percentage. The percentage depends
on your service type.
General service:
1.67% × years of service credit × monthly final average salary = monthly pension benefit
Police and firefighters:
2% × years of service credit × monthly final average salary = monthly pension
benefit
Money Match
(Tier One and Tier Two)
Your member account balance is matched by your employer, and the result is multiplied by a variable representing
the estimated life expectancy for people in your age group (aka your “age factor”).
Age factor × account balance × 2
Formula Plus Annuity
(only Tier One members who made contributions before August 21, 1981)
This method has two parts, the first of which is similar to Full Formula but uses a different set percentage.
Your total from this first part is then added to an annuity payment, which is calculated by multiplying your
member account balance by a variable representing the estimated life expectancy for people in your age group
(aka your “age factor”). This second part looks similar to the Money Match formula.
General service:
1% × years of service credit × final average salary + Age factor × account balance
Legislators, police, and firefighters:
1.35% × years of service credit × final average salary + Age factor
× account balance
Notes:
- Most Tier One/Tier Two members now retire under the Full Formula method. Tier Two members are unlikely to
have Money Match result in their highest calculated benefit because their account balances are generally low
(due to having fewer years of contributions into the member account before 2004, when contributions were
diverted to the IAP).
- In general, your final average salary is the greater of these amounts:
- The average gross monthly salary that results from the three years in which you earned your highest
total salaries from one or more PERS-participating employers, even if one of those years was less
than a full calendar year.
- 1/36 of the total salary you received from one or more PERS-participating employers in the last 36
months of active membership.
A note about overtime
House Bill (HB) 2728 (2025) requires PERS to explain to retiring members how overtime hours were used in calculating
their final average salary (FAS). This information will be included in a member’s notice of entitlement letter (NOE),
which officially tells a member what their monthly pension benefit will be.
As of January 1, 2026, NOEs must provide both of the following:
-
The total number of overtime hours the member accrued during the time period used to calculate their FAS.
AND
-
The number of overtime hours used in the FAS calculation.
For Tier One and Tier Two members, no cap on overtime exists, so the number of overtime hours accrued and the number
used in the FAS calculation will be the same.