The COBRA and Medicare Trap That Costs Retirees

This is one of the most expensive misunderstandings in all of Medicare, and it hits people who did everything they thought was reasonable. When you leave a job around age 65, COBRA lets you keep your employer health plan for a while, and it feels natural to lean on it and put off Medicare. The problem is that for Medicare purposes, COBRA does not work the way people assume. It is not the kind of coverage that lets you safely delay Part B, and treating it as if it does can leave you with a lifelong penalty and a gap in coverage. Understanding this before you make a decision is what keeps you out of the trap.

Bryce's Take

This is the mistake that genuinely keeps me up, because the people who make it are being reasonable. They leave a job, they take COBRA because it is familiar, and nobody tells them COBRA does not let them delay Part B. Months later they have a penalty they cannot undo and claims that are not being paid. If you are turning 65 and someone offers you COBRA, please talk to me before you skip Part B. This is a five-minute conversation that can save you a lifelong surcharge.

Why people fall into the COBRA trap

The trap is intuitive. You are turning 65, you are leaving or have left a job, and COBRA lets you continue the health plan you already know. Since you have coverage, skipping Part B and its monthly premium seems like a sensible way to save money for a while. Many people assume that because COBRA is real, employer-based health insurance, it counts the same as active employer coverage for delaying Medicare. It does not, and that single wrong assumption is what causes the damage down the road.

COBRA is not creditable coverage for Part B

For the purpose of delaying Part B without penalty, COBRA is not considered creditable coverage based on current employment. The rule that lets you delay Part B penalty-free is tied to coverage through active, current employment, yours or a spouse's. COBRA is a continuation of coverage after employment has ended, so it does not meet that standard. That means the clock on your Part B enrollment window keeps running while you are on COBRA, and Medicare generally becomes the primary payer once you are eligible, whether or not you have actually enrolled in Part B.

The two costs of getting this wrong

Getting this wrong tends to cost you twice. First, the late enrollment penalty: if you skip Part B when first eligible and do not have qualifying active-employment coverage, you can face a permanent Part B penalty that gets added to your premium for as long as you have Medicare. It is not a one-time fee, it is a lifelong surcharge. Second, the coverage gap: because Medicare becomes primary once you are eligible, COBRA may pay little or nothing on claims it assumes Medicare should have covered, leaving you exposed on bills you thought were covered. You can end up penalized and underinsured at the same time.

What you should generally do instead

The safer approach in most cases is to enroll in Part B when you are first eligible, even if you also have COBRA. Enrolling in Part B on time protects you from the late enrollment penalty and makes sure Medicare, as the primary payer, is actually in place. Some people keep certain COBRA coverage alongside Medicare for specific reasons, such as dental or a spouse still on the plan, but that is a deliberate choice made with Medicare in place, not a substitute for enrolling in Part B. And critically, COBRA does not extend your Part B special enrollment period, so waiting until COBRA ends to enroll does not protect you the way it would with active-employment coverage.

If you are already in the trap

If you have already taken COBRA and skipped Part B, do not simply wait for COBRA to run out. Because COBRA does not trigger a special enrollment period for Part B, letting it lapse can leave you waiting for the next general enrollment window with a penalty attached. The right move is to look at your timing carefully and enroll in Part B as soon as you appropriately can to limit the penalty and close the coverage gap. This is exactly the kind of situation where a quick conversation before you make your next move can save you real money and a lot of aggravation.

Bryce Casson

Licensed Independent Medicare Broker

Bryce Casson is an independent Medicare insurance broker who works with every major carrier. He does not represent any single insurer, which means his recommendations are based on what actually fits each client's situation, not on commissions or quotas.