Montana Public Employee Retirement Administration

Buying Service Credit

Defined Benefit members may enhance their retirement benefit by purchasing prior refunded service, prior Montana service and other federal employment time.  For a full list of the types of service you can purchase, check the individual retirement system web pages.


If you are currently working and contributing to a retirement plan, you are considered an 'active member'. As an active member, you can purchase service at any time before retirement. Purchasing service may enhance your retirement benefit.

If you are an inactive vested member (have five years of membership service but are no longer employed in a contributing position), you may purchase any service for which you are eligible any time prior to retirement at the actuarial cost of the service purchase, based on your age at the time of the request and your salary at the time of your most recent termination. Interest equal to the actuarial rate of return for the trust fund at the time of your termination will be charged and compounded monthly until you complete payment for the cost of the purchase.

Cost Statements

If you wish to purchase service, you must request an official cost statement.

Requesting a cost statement: A cost statement will tell you the amount you would be required to pay for the service you are interested in buying. To make a request, contact MPERA with following information:

  • your full name (including any former names),
  • a current mailing address,
  • Person Account ID, (contact MPERA if you do not know this)
  • current employer and 
  • the type of service you wish to buy.

With your request, you will need to send any documents that relate to the service, including:

  • the approximate dates of service,
  • your current retirement system and 
  • the name of the employer for whom service was performed.

We will review the request and send you a cost statement and the necessary form for buying any eligible service.

Paying For Your Service

You can pay for a service purchase in one lump-sum within 30 days of the date of your cost statement or make monthly payments. If you are an active member, you can make monthly payments by pre-tax payroll deduction. You can also purchase service by rolling over funds from an eligible retirement plan. Payment is subject to interest if not paid as a lump-sum.

Inactive and/or vested (you have more than five years of membership service) members, active members who are not paid at least once per month, or active members who wish to pay in a lump-sum, can send payments directly to MPERA. These payments are not made pre-tax.

If you fail to make a regular monthly payment, you give up the right to make any more payments. Your service purchase contract will terminate and the service credit will be prorated based on the amount paid.


Current law limits the purchase of active military, reserve military, "One-for-Five", and other public service to a combined total of five years. When purchasing service, your most recent service must be purchased first.

Click on the retirement system to see what types of service are available to purchase.