If you have a balance in both a Flexible Spending Account and HRA VEBA, reimbursement will be made from your FSA first since this is a use or lose plan and the HRA VEBA second.
For example, if you submit a claim for $500 and have $400 in your FSA and $5,000 in your HRA VEBA, you will receive $400 from your FSA and the remaining $100 from your HRA VEBA. Once you exhaust your FSA, all reimbursements will be made from the HRA VEBA.