Creditable prescription drug coverage is insurance expected to pay, on average, at least as much as standard Medicare Part D. It can come from a current or former employer or union, TRICARE, Veterans Affairs, the Indian Health Service, or another qualifying source.

Your plan determines whether its drug coverage is creditable under Medicare rules. That status applies to drug coverage; it does not give you a general right to delay Part B. Discount cards, free samples, and cash-discount websites are not creditable drug insurance.

Why Does It Matter?

If you go 63 consecutive days or more without Part D or other creditable drug coverage after your Initial Enrollment Period ends, Medicare may add a late-enrollment penalty when you eventually join Part D.

The penalty is generally added to your premium for as long as you have Medicare drug coverage.

How Do You Know Coverage Is Creditable?

Your employer, union, or plan must tell you. It generally sends a notice each year and when coverage changes.

Keep the notice permanently. A new Part D plan may ask you to prove the dates of prior creditable coverage.

Do not guess based on how generous the plan seems. Ask the benefits administrator directly: “Is this prescription coverage creditable for Medicare Part D?”

What Happens When Coverage Ends?

For involuntary loss of creditable drug coverage, you generally have through two full months after the month you lose coverage or are told it is no longer creditable, whichever is later, to make a plan change. This enrollment deadline is separate from the 63-day rule for a penalty. Arrange the new start date before a gap develops; use Medicare’s loss-of-coverage rules.

Also ask whether joining Part D could cause you or a dependent to lose employer or retiree health benefits.

See Medicare's official creditable coverage explanation.

Keep each creditable-coverage notice with the dates the insurance actually covered you. If the plan’s status changes, use the new notice to arrange Part D and get written confirmation of when coverage will start.

Medicare policy sources last checked: October 8, 2026.