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Working Past 65: Medicare, Employer Coverage, COBRA and HSA Rules

By Modinul Islam Khan Updated October 1, 2026

Reviewed September 17, 2026. Working after age 65 can change when you should enroll in Medicare. The answer depends on whose employment provides the coverage, whether that employment is current, the employer’s size, HSA contributions, and the date work or coverage ends.

Use Medicare’s official questionnaire for an individualized starting point. Check when you can sign up on Medicare.gov.

First question: is the coverage based on current employment?

Medicare distinguishes group coverage based on current employment from COBRA and retiree coverage. COBRA is not treated as current-employment group coverage for the Part B Special Enrollment Period. Read Medicare’s Special Enrollment Period rules.

Ask the employer these questions

Is this coverage based on my current employment or my spouse’s current employment?
How many employees does the employer have?
After age 65, does the employer plan pay before or after Medicare?
Must I enroll in Part A or Part B to keep the employer coverage?
Is the prescription coverage creditable for Medicare Part D?
When will employment and group coverage end?
Is anyone contributing to an HSA?

Medicare advises people with employer coverage to ask the employer how the plan works with Medicare. A small employer’s plan may not pay properly when a Medicare-eligible worker has not enrolled in Medicare. Review Medicare’s working-past-65 guidance.

Part B Special Enrollment Period

Someone who delayed Part B because of qualifying group coverage based on current employment can generally enroll while still covered or during the eight-month period beginning after the employment or coverage ends, whichever occurs first. Coverage generally starts the month after enrollment. Missing that period can cause a coverage gap and a late-enrollment penalty. Verify the current timing on Medicare.gov.

Why COBRA is different

COBRA can continue an employer plan after employment ends, but Medicare states that COBRA does not extend the eight-month Part B Special Enrollment Period. The employment or active-employment coverage ending can start that clock even when COBRA continues. See Medicare’s COBRA warning.

Health Savings Account timing

The IRS states that the HSA contribution limit becomes zero beginning with the first month a person is enrolled in Medicare. If premium-free Part A is later backdated, contributions made during the retroactive coverage period can be excess contributions. Read the Medicare enrollment rule in IRS Publication 969.

Do not choose an HSA stopping date from a general article alone. Confirm the Medicare effective date with Social Security and the contribution deadline with the employer benefits office and a qualified tax professional.

When employment is ending

Get the employer coverage end date in writing.
Ask the employer to complete the evidence Social Security requires for employment-based coverage.
Apply for Part B early enough to avoid a gap.
Confirm the Part A and Part B effective dates before ending other coverage.
Compare Part D, Medicare Advantage, and Medigap options using the correct enrollment windows.

Social Security provides the Part B application and the CMS-L564 employment-information form used for an employment-based Special Enrollment Period. Review the current Part B enrollment process on SSA.gov.

Decision checklist

☐ Coverage is based on current employment.
☐ Employer size and payer order are confirmed.
☐ Prescription coverage is confirmed as creditable.
☐ Part B Special Enrollment Period dates are written down.
☐ COBRA and retiree coverage are not being mistaken for active-employment coverage.
☐ HSA contributions are coordinated with the Medicare effective date.
☐ Replacement coverage starts before employer coverage ends.

This guide provides general Medicare information. Rules can differ for disability, End-Stage Renal Disease, foreign employment, federal employee coverage, TRICARE, VA benefits, and other circumstances.