Past Service

for Tier 2 SLEP Plan Members
Seaside rocks

You may be eligible to purchase service credit for a variety of different reasons: for example, to reinstate a refund or to convert time served in the military.

Regardless of the type of service you are purchasing or converting, you are purchasing “Past Service.” See Types of Past Service and How to Apply for information about the kinds of service you may be able to purchase through IMRF.

Buying Past Service

If you are able to purchase past service, you could increase the amount of your pension. Your IMRF pension amount is based on your years of IMRF service credit, your age, and an average of your salary. Purchasing past service increases your total service credit, which will increase the amount of your pension.

When you purchase past service, you are guaranteed a 100% return of these contributions in the form of a pension, refund, or death benefit.

Buying Service Often Increases Your Pension

The amount of your IMRF pension is partially determined by the amount and type of service credit you have. If you have previously taken a refund of IMRF contributions or are eligible for other types of past service credit, you can buy back this service to increase the amount of your pension.

Paying back a refund is the most common type of past service purchased. You can complete your "Reinstatement of Service Credit" application quickly and easily through Member Access.

There are situations where buying service is not worth the cost. Read more about Deciding Whether to Purchase Past Service.

The Cost of Purchasing Past Service

To find out how much it will cost you to purchase your past service, you must complete and return a past service application to IMRF. The type of application you fill out depends on the type of service you are eligible to purchase.

After you send in your application, you will receive a payment schedule that shows your cost to purchase:

Learn more about ways to pay for past service.

The Past Service Process

  1. Start by looking at the list of Types of Past Service and How to Apply and determining which type applies to you.
  2. Read more about Deciding Whether to Purchase Past Service.
  3. Apply for the type of past service you are interested in purchasing.
  4. When IMRF receives your form, we will determine your eligibility and send out a payment schedule. Learn more about payment schedules.
  5. To determine whether purchasing past service makes sense for you, request estimates from IMRF.
  6. If you don’t decide whether to purchase your service within a year of starting the process, you may want to call IMRF and request an updated schedule.


If you have any questions about purchasing service, please contact IMRF by Secure Message using your Member Access account or by calling an IMRF Member Services Representative at 1-800-ASK-IMRF (275-4673) 7:30 AM to 5:30 PM, Monday through Friday.