COBRA continuation coverage is one of the most misunderstood concepts in US health insurance, especially at age 65. Thousands of people each year assume that keeping COBRA after turning 65 protects them from Medicare deadlines. That assumption costs them thousands of dollars in lifetime penalties. Medicare rules are clear on this point: COBRA is not active employer coverage. The Special Enrollment Period that lets workers delay Part B without penalty is reserved for people who are still actively employed at a job with a group health plan sponsored by an employer with 20 or more employees. COBRA, retiree health plans, individual market plans, and severance coverage do not qualify. Turning 65 while on COBRA means your 7-month Initial Enrollment Period (IEP) is running whether you use it or not. Missing it triggers a 10% Part B premium penalty for every 12-month period you were eligible but did not enroll, and that penalty follows you for the rest of your life. At the 2026 standard Part B premium of $202.90 per month, two years of delay adds roughly $40 per month, permanently. Over a 20-year retirement, that compounds to more than $9,600 in unnecessary cost.
Medicare eligibility is not the same as COBRA eligibility, and the two clocks run independently. COBRA gives you 18 months (or up to 36 months for certain qualifying events like divorce or death of the covered employee) of continued group coverage after your active employment ends. Medicare IEP gives you exactly 7 months centered on your 65th birthday to enroll in Part A and Part B. If you leave your job at 63 and spend two years on COBRA, you will turn 65 while still on COBRA, and your IEP will open 3 months before your 65th birthday month regardless of how much COBRA time you have left. Many people in this situation hold COBRA through the IEP because they do not realize the deadline is passing. The right action for almost everyone turning 65 on COBRA is to enroll in Medicare Part A and Part B during the IEP, and then use Medicare as primary payer with COBRA stepping in as secondary for any cost-sharing gaps. Medicare eligibility and enrollment rules come from medicare.gov and the Social Security Administration at ssa.gov. Check the Medicare eligibility requirements section before making any enrollment decision based on a broker recommendation or plan comparison alone.
7 Steps to Get Coverage
Common Mistakes That Cost People Thousands
The most costly mistakes people on COBRA make around their 65th birthday. Most of these penalties are permanent:
- Assuming COBRA protects you from the Part B enrollment deadline. COBRA is NOT active employer coverage under Medicare rules. The 8-month SEP for delaying Part B applies only to people with active employer plans from current employment at a company with 20 or more employees. On COBRA, your IEP clock is ticking.
- Waiting until COBRA ends to enroll in Medicare. If your IEP already passed while you were on COBRA, you must wait for the General Enrollment Period (January 1 to March 31), pay the late penalty, and start coverage July 1. That gap and penalty are both avoidable by enrolling during the IEP.
- Skipping Part B because Part A is free. Part A covers hospital inpatient care but does not cover outpatient doctor visits, lab work, durable medical equipment, or most specialists. Part B covers all of those, and skipping it leaves a major coverage gap. COBRA filling in for Part B is expensive insurance when Medicare Part B at $202.90 per month would cover the same services as the primary payer.
- Missing the 6-month guaranteed-issue Medigap window. If you choose Original Medicare, your guaranteed-issue window for Medigap opens the first month you are both 65 and enrolled in Part B. After it closes, Medigap insurers in most states can deny you or charge significantly more based on your health history.
- Going without Part D drug coverage for more than 63 days. Even if your current COBRA plan includes drugs, verify in writing that the drug coverage is creditable (as good as standard Part D). Non-creditable drug coverage triggers the 1% per month lifetime Part D late penalty for every month without qualifying drug coverage after your Part B effective date.
- Paying for COBRA without comparing it to Medicare plus a Medigap plan. COBRA at 102% of the full group premium often costs $500 to $900 per month for individual coverage. Medicare Part B at $202.90 plus a Medigap Plan G at $100 to $200 per month frequently delivers equivalent or better coverage at lower total cost, especially once Medicare becomes your primary payer.
COBRA vs Medicare as Primary Payer: How They Work Together
Medicare Secondary Payer (MSP) rules govern what happens when a Medicare-eligible person also has other coverage. For someone turning 65 on COBRA, the rule is straightforward: Medicare pays first (primary), and COBRA pays second (secondary) for any remaining cost-sharing. COBRA is explicitly designed under the Medicare Secondary Payer statute to yield to Medicare once the person becomes Medicare-eligible and actually enrolls. This means keeping COBRA after enrolling in Medicare Part A and Part B can make sense as a short-term gap filler. COBRA may cover your Part A hospital deductible ($1,736 in 2026), your Part B 20% coinsurance for outpatient services, and Part B's $283 annual deductible. Whether the COBRA premium is worth those benefits depends entirely on your remaining COBRA period, your health status, and whether a Medigap plan would serve you better for less.
Three coverage scenarios are common for someone on COBRA who turns 65. Scenario 1: Retire or leave job before 65, then turn 65 while still within the COBRA period. The IEP opens 3 months before the 65th birthday month. Enroll in Medicare during the IEP, Medicare becomes primary, COBRA becomes secondary. Scenario 2: Still employed at age 65 at a 20-employee plan, then retire and elect COBRA. The 8-month SEP for delaying Part B starts from the end of active employment (or end of the employer group plan, whichever is first), not from the end of COBRA. The 8-month clock is your window. Scenario 3: Turn 65 while on a former spouse's COBRA following divorce. Divorce triggers a COBRA qualifying event, but the resulting COBRA coverage does not count as active employer coverage. The IEP based on the 65th birthday governs.
Part D Drug Coverage and COBRA: What Counts as Creditable Coverage
Part D prescription drug coverage rules differ from Part B rules when COBRA is involved. For Part B, COBRA never counts for delay purposes. For Part D, COBRA drug coverage MAY count as creditable coverage if the plan actuary certifies it meets or exceeds the standard Part D benefit level. Most major group health plans that include drug coverage (including many COBRA plans) do qualify as creditable. Your employer plan administrator is required to send you a Notice of Creditable Coverage or Non-Creditable Coverage each fall, and again when your coverage changes. Keep that notice. If your COBRA drug coverage is creditable, you can delay Part D enrollment without penalty for as long as your COBRA drug coverage continues. Once COBRA ends, you have 63 days to enroll in a Part D plan without penalty.
Medicare Part D in 2026 has an out-of-pocket cap of $2,100 under the Inflation Reduction Act, a significant improvement from pre-IRA years. The $35 per month insulin cap also applies to Medicare Part D plans in 2026. Before deciding whether to keep COBRA drug coverage or switch to a Part D plan immediately, compare your specific drug list against Part D plan formularies at medicare.gov using the plan finder tool. Lower-income enrollees may qualify for Extra Help (Low-Income Subsidy), which caps Part D premiums near $0 and reduces copays to a few dollars per prescription. Apply for Extra Help at SSA.gov.
The 8-Month Special Enrollment Period: When It Applies and When It Does Not
The Medicare Part B Special Enrollment Period for workers past 65 is 8 months, starting from the end of active employment or the end of the employer group health plan coverage, whichever comes first. This SEP is the protection that lets someone still working past 65 delay Part B without penalty. Understanding exactly when this SEP applies requires answering three questions: Are you (or your spouse) currently employed? Does the employer have 20 or more employees? Are you enrolled in the employer's active group health plan right now? All three must be yes for the delay to be penalty-free. Once employment ends, the 8-month SEP begins regardless of whether COBRA is elected. Electing COBRA does not restart the 8-month clock and does not give you a new SEP. If you let the 8-month SEP expire while on COBRA (thinking COBRA was extending your deadline), you will owe the late penalty.
Retiree health plans operate under the same rule as COBRA for Medicare enrollment purposes: they do not count as active employer coverage and do not trigger the 8-month SEP. The same applies to coverage from a spouse's COBRA, severance-based coverage, and individual market plans. The only coverage that lets you delay Part B at 65 without penalty is an active group health plan from current employment at a covered employer (20 or more employees). Medicare.gov's working-past-65 section at medicare.gov/basics/get-started-with-medicare/medicare-basics/working-past-65 has the authoritative guidance. Your State Health Insurance Assistance Program (SHIP) offers free counseling to help you navigate enrollment decisions: find your SHIP at shiptacenter.org.
2026 Medicare Cost Summary for New Enrollees Turning 65 on COBRA
Understanding the 2026 Medicare cost structure helps you decide whether to keep COBRA as secondary coverage, add Medigap, or switch to Medicare Advantage. Part A (hospital insurance) is premium-free for people (or spouses) with 40 or more quarters of Medicare-covered work. Those with 30 to 39 quarters pay $311 per month. Those with fewer than 30 quarters pay $565 per month. Part A carries a $1,736 per-benefit-period hospital deductible in 2026. Part B (medical insurance) costs $202.90 per month at standard premium with a $283 annual deductible and 20% coinsurance after the deductible on most outpatient services. Higher-income enrollees pay IRMAA surcharges. Part D out-of-pocket is capped at $2,100 for 2026 under the Inflation Reduction Act. Medicare Advantage plans in 2026 have a federal in-network out-of-pocket maximum ceiling of $9,250. Medigap Plan G covers the Part B deductible, the Part A deductible, and Part B coinsurance, with premiums ranging from roughly $100 to $300 per month depending on age, location, and insurer.
2026 Medicare Standard Cost Reference: Part A, Part B, Part D| Coverage | 2026 Premium | 2026 Deductible / Cost-Sharing |
|---|
| Part A (40+ quarters) | $0/mo | $1,736 per hospital benefit period |
| Part A (30-39 quarters) | $311/mo | $1,736 per hospital benefit period |
| Part A (less than 30 quarters) | $565/mo | $1,736 per hospital benefit period |
| Part B (standard) | $202.90/mo | $283/yr deductible + 20% coinsurance |
| Part D (varies by plan) | $0 to $80/mo typical | $2,100 annual OOP cap (IRA 2022) |
| Medicare Advantage (Part C) | $202.90/mo Part B + $0 to $50 plan premium (often $0) | Federal MOOP ceiling $9,250 in-network (2026) |
| Medigap Plan G (typical) | $100 to $300/mo | Covers Part B deductible, Part A deductible, Part B coinsurance |
Source: CMS 2026 Medicare Parts A and B Premiums and Deductibles fact sheet. IRMAA surcharges apply to Part B and Part D for higher-income enrollees. Medicare Advantage plan premiums vary by carrier and county. Medigap premiums vary by state, age, and insurer.
Source: CMS 2026 Medicare Parts A and B Premiums and Deductibles; Medicare.gov plan finder; IRS Rev. Proc. 2025-19
Frequently Asked Questions
Do I need to enroll in Medicare Part B if I have COBRA coverage after turning 65?
Yes, in almost every case. COBRA is not treated as active employer coverage under Medicare rules, so it does not let you delay Part B enrollment. Your 7-month Initial Enrollment Period (IEP) opens 3 months before your 65th birthday month and closes 3 months after. Miss it without a qualifying exception, and you face a 10% per year permanent penalty on your Part B premium. At the 2026 standard premium of $202.90 per month, two years of delay adds roughly $40 per month for the rest of your life. The only situation where you can delay Part B penalty-free is if you are currently employed at a company with 20 or more employees and enrolled in that active group health plan.
When exactly does my Medicare Initial Enrollment Period start if I am on COBRA?
Your Initial Enrollment Period (IEP) is based entirely on your 65th birthday, not on your COBRA start or end date. The IEP opens on the first day of the month that is 3 months before your birthday month and closes on the last day of the 3rd month after your birthday month. Example: if your birthday is November 20, 2026, your IEP runs August 1, 2026 through February 28, 2027. COBRA has no bearing on these dates. Enroll in the first 3 months of the IEP for Part B coverage to begin on your birthday month. Enroll later in the IEP and coverage starts the month after enrollment.
What happens if I wait until my COBRA runs out to enroll in Medicare?
If your IEP already passed by the time your COBRA ends, you will need to wait for the Medicare General Enrollment Period (January 1 through March 31 each year), with Part B coverage starting July 1 of that year. You will also pay a permanent Part B late enrollment penalty of 10% for each 12-month period you were eligible but not enrolled. Additionally, if your COBRA drug coverage was not creditable, you will also owe a Part D late penalty. The only way to avoid these penalties is to enroll in Part B during your 7-month IEP or within the 8-month SEP that starts when active employer coverage ends.
Is COBRA drug coverage creditable for Medicare Part D?
Whether COBRA drug coverage counts for Part D delay depends on your specific plan. Unlike Part B rules, where COBRA never counts for delay, COBRA drug coverage CAN be creditable for Part D if the plan actuary certifies it meets or exceeds the standard Part D benefit. Your plan administrator is required to send you a Notice of Creditable or Non-Creditable Coverage each fall and when your coverage changes. Keep this notice. If it says creditable, you can delay Part D without penalty while COBRA drug coverage continues. Once COBRA ends, you have 63 days to enroll in a Part D plan without penalty. Contact your COBRA administrator directly if you did not receive the notice.
Can I keep COBRA alongside Medicare?
Yes. After you enroll in Medicare Parts A and B, you can keep your COBRA coverage running as secondary insurance for whatever time remains on your COBRA clock (up to 18 months from your qualifying event, or up to 36 months for certain events). Under Medicare Secondary Payer rules, Medicare pays first and COBRA pays second, potentially covering your Part A hospital deductible ($1,736 in 2026), your Part B 20% coinsurance, and your Part B deductible ($283 in 2026). Whether keeping COBRA as secondary is cost-effective compared to a Medigap plan depends on your COBRA premium, remaining COBRA months, and your expected healthcare use.
What if I retired early and have been on COBRA for a year before turning 65?
Early retirement before 65 followed by COBRA is the most common scenario people face. If you retired before 65 and elected COBRA, your Medicare IEP opens on its normal schedule: 3 months before your 65th birthday month, the birthday month, and 3 months after. Your COBRA clock and Medicare IEP are completely independent of each other. Enroll in Medicare Parts A and B during your IEP. Once Medicare is active, it becomes your primary payer and COBRA becomes secondary for whatever COBRA time remains. Many people in this situation elect to keep COBRA as secondary through the end of their COBRA period, then switch to a Medigap or Medicare Advantage plan when COBRA expires.
Do I automatically get enrolled in Medicare at 65 if I am on COBRA?
No. Automatic enrollment in Medicare Parts A and B at 65 only occurs if you are already receiving Social Security or Railroad Retirement Board benefits before your 65th birthday. If you retired and are on COBRA but not yet collecting Social Security (which is common for people who delay claiming to age 67 or 70), you must actively enroll in Medicare. Apply at SSA.gov/medicare or call 1-800-772-1213. Most financial planners recommend delaying Social Security for the higher benefit, but this means Medicare enrollment is not automatic.
What is the Medicare General Enrollment Period and when do I use it?
The Medicare General Enrollment Period (GEP) runs January 1 through March 31 each year, with Part B coverage starting July 1 of the same year. The GEP is your fallback if you missed the 7-month IEP and do not qualify for a Special Enrollment Period. During the GEP, you can sign up for Part A and Part B. If you missed your IEP while on COBRA, call Social Security at 1-800-772-1213 to calculate your late penalty and confirm your GEP enrollment options. The penalty begins accruing from the month after your IEP ended, not from the date COBRA ends.
