HIPAA privacy rules and high security standards prevent health care providers from freely sharing those details with anyone that requests them. So, when it's possible the expense is ineligible and information is not available, you receive a request for substantiation.

What is a substantiation process?

Debit card substantiation is the process of verifying that purchases made using a benefits debit card for FSAs or HRAs were for an eligible medical expense. These purchases must be substantiated per IRS guidelines.

What is the meaning of substantiation in accounting?

noun. evidence sufficient to establish a thing as true, valid, or real; proof: The department may require employees to provide vouchers, receipts, or other substantiation for any fees or expenses claimed.