If you didn’t use Flex at checkout to generate an itemized receipt, reimbursement may be more challenging.For Health Savings Accounts (HSAs), you're usually able to submit an itemized receipt for reimbursement at any time, even years after the purchase.For Flexible Spending Accounts (FSAs), most plans require that the purchase be made during the same calendar year the funds were available, as FSA funds typically don’t carry over. However, some plans offer a grace period or buffer window, allowing extra time to submit receipts for eligible expenses from the previous year.