IRMAA Basics
Understanding Creditable Coverage Criteria for Medicare A, B, and D
Verified against SSA POMS as of September 20, 2026
The short answer
Creditable coverage for Medicare A, B and D is generally understood as coverage that has benefits that meet or exceed Medicare health coverage and pays, on average, as much as standard Medicare prescription drug coverage.
Definition of Creditable Coverage
Creditable coverage refers to health insurance or prescription drug coverage that provides benefits equal to or better than Medicare Parts A and B or pays on average at least as much as standard Part D coverage. For employer health plans, creditable coverage typically means the plan covers at least 20 employees and offers benefits that meet or exceed those of Original Medicare. Having creditable health and drug coverage allows individuals to delay enrolling in Medicare when they first become eligible without facing penalties if they choose to enroll in Medicare at a later date.
CMSPDF:medicare/eligibility-and-enrollment/medicarepresdrugeligenrol/downloads/final_cy2010_medicareprescriptiondrugbenefitmanualchapter4_dec2009.pdf View source ›Responsibility for Determinations
Entities offering prescription drug coverage must determine its creditable status annually and inform Medicare-eligible individuals. This includes employers, unions, and group health plans. The determination uses generally accepted actuarial principles. CMS mandates that employers issue written notices to Medicare-eligible employees before October 15 each year regarding the creditable status of their Part D prescription drug coverage. While there is no formal CMS creditability testing or annual filing required for Medicare Part B, exemptions from late penalties depend on the group health plan status tied to current active employment, typically involving an employer with 20 or more employees.
CMSPDF:medicare/eligibility-and-enrollment/medicarepresdrugeligenrol/downloads/cclepguidance20070612.pdf View source ›Disclosure Requirements
Entities must disclose whether their coverage is creditable to CMS and the beneficiaries. This must be done annually and whenever the status changes. Non-creditable coverage requires disclosure to prevent late enrollment penalties.
CMSPDF:medicare/prescription-drug-coverage/creditablecoverage/downloads/2007-09-25_ccdisclosure2cmsinstructionsscreenshots.pdf View source ›Impact of Non-Creditable Coverage
Medicare beneficiaries without creditable coverage for 63 days or more may incur a late enrollment penalty if they join Medicare Part D later. This penalty is calculated based on the period without creditable coverage. Additionally, for Medicare Part B, penalties begin at the end of the initial enrollment period. Every 12-month period without Part B coverage results in an additional 10% penalty on top of the Part B premium.
CMSPDF:medicare/eligibility-and-enrollment/medicarepresdrugeligenrol/downloads/creditablecoveragelepguidanceupdate041108.pdf View source ›Simplified Determination
If a plan's design meets certain criteria, such as covering at least 60% of prescription expenses, it may automatically be deemed creditable. This applies to non-integrated plans as defined in CMS simplified guidance.
CMSPDF:medicare/prescription-drug-coverage/creditablecoverage/downloads/ccsimplifieddetermination.pdf View source ›Frequently asked
What makes coverage 'creditable' for Medicare Part D?
Coverage is 'creditable' if it matches or exceeds the value of standard Medicare prescription drug coverage in terms of expected paid claims.
How does non-creditable coverage affect me?
Having non-creditable coverage for more than 63 days can result in a late enrollment penalty if you decide to join Part D later. Additionally, non-creditable coverage may lead to penalties for Medicare Part B for each 12-month period of non-coverage beyond the Initial Enrollment Period (IEP). To avoid these penalties, consider enrolling in Original Medicare during your IEP, even if you have other coverage options.
Do all plans need to disclose creditable coverage status?
Yes, all entities offering prescription drug coverage to eligible Medicare individuals must disclose whether their coverage is creditable annually.
Can simplified determination certify any plan as creditable?
Yes, if a plan meets specific criteria outlined in CMS guidance, it can be deemed creditable through simplified determination.
What should I do if my coverage isn't creditable?
Consider enrolling in Original Medicare and a Medicare Part D plan during your initial enrollment period to avoid potential penalties.