You're only allowed to claim medical expenses that you already paid to the provider.
For example, if you're making monthly payments to the hospital for last year's operation, you can only deduct what you paid so far, not what the total operation will eventually cost you.
But if you charged the entire bill to your credit card which you're still paying off, you can claim the full cost.
The IRS defines the "paid date" as:
- The date you put the bill on your credit card
- The date you mailed or delivered the check or money order
- The date the charge appeared on your statement, if you paid the bill online or via telephone