In IRS Information Letter 2021-13, the agency reiterates that Flexible Spending Account (FSA) claims paid on an FSA debit card must have the required substantiation, containing all of the information normally required for a claim submitted for reimbursement through other means such as mail, e-mail, or fax. The only exception to those rules are for those expenses received at certain providers (pharmacies, for example) that can be auto-substantiated by both the Merchant Category Code (MCC) of the provider’s debit card machine as well as the actual item or service received as identified by an Inventory Information Approval System (IIAS) from any non-health care provider.