Anything showing provider, patient, date of service, description of the service, and your out-of-pocket amount. An itemized bill or an EOB works; a card swipe slip usually does not.
A defensible receipt answers five questions:
- Who provided the service? (provider or pharmacy name)
- Who received it? (patient name)
- When? (date of service)
- What was it? (description — cleaning, exam, prescription name)
- How much did you pay? (your out-of-pocket amount, after insurance)
Documents that generally satisfy this:
- Itemized statements or superbills from a provider
- Insurance Explanation of Benefits showing patient responsibility
- Pharmacy printouts (the tall receipt with the drug name, not the register slip)
- Detailed invoices from dental and vision offices
Documents that generally don't, on their own:
- Credit card slips showing only a merchant name and total
- Bank statement lines
- Appointment reminders
- "Paid in full" notes with no service description
When in doubt, keep both the EOB and the provider statement. Storage is cheap; reconstruction in 2046 is not.