Unlike a health FSA which requires any unused funds to be forfeited, an HRA can be set up to roll your funds from one plan year to the next. If your employer offers "fund rollover" it will be described in your Summary Plan Description.
Here's who HRA fund rollover typically works: at the end of the plan year, you will have a certain amount of time ("run-out period") to submit claims for services incurred during the prior year. At the end of the run-out period, or at a date set by your employer, all or a portion of your remaining funds may rollover to the next plan year or to a carryover account. Your employer may set the following rules:
1) A Percentage of remaining funds may rollover, such as 50%. So, if you have $512 on the fund rollover date, you can rollover $256.
2) A Maximum amount may rollover, such as $250. Taking the example above, only $250 would rollover of the remaining $512.
3) A Percentage up to a Maximum, such as 50% up to $250. Again, $250 would rollover, using the example above. If you had $300 remaining, then only $150 would rollover (50% of $300).
4) All funds - all remaining funds may rollover to the next plan year.