Your pensionable service is a key part in the formula used to calculate your future LAPP pension. The more service you have when you retire, the larger your pension will be. You earn service every day you contribute to the plan, but sometimes you are allowed to buy service.
If you are off work for a period of leave and not paid (Leaves of Absence), this will create a gap in your pensionable service. You can buy this service to ensure there is no service gap.
If you were paid out for service you earned with another Registered Pension Plan (RPP), you can use those funds to buy pensionable service in LAPP. (Buying Prior Service). You can also purchase service from a period when you were held out by your employer from contributing to the Plan, for up to one year. This is called probationary service.
We call buying service these ways a buyback.