Newsroom · Colorado

Can I Keep COBRA Instead of Medicare at 65 in Colorado?

Almost never safely. COBRA is not current-employment coverage — which means a clock you can't see started the day you cleaned out your desk.

Medicare On Main Data Desk

Published August 25, 2026 · 9 min read · Reviewed by Brian Penner

This is the question that walks into our Grand Junction office with a folder already open. Someone retired at 64, took COBRA because it was the familiar plan with the familiar doctors, turned 65 somewhere in the middle of it, and figured they'd deal with Medicare when the COBRA ran out. It's a completely reasonable assumption. It's also the single most expensive misunderstanding in Medicare, and unlike most of them, it is quiet — nothing arrives in the mail to tell you the clock is running.

Can I keep COBRA instead of Medicare at 65?

You can physically keep paying the premium. What you cannot do is use COBRA as a reason to postpone Part B without consequences, because Medicare doesn't count it. The rule Medicare actually applies is narrower than most people think: you may delay Part B penalty-free when you have group health coverage based on current employment — yours or a spouse's. COBRA is, by definition, the coverage that continues after employment ends. That's the whole disqualification, and it fits in one sentence.

Medicare.gov's own COBRA page states the timing without any hedging: "You have up to 8 months after you stop working (or lose your health insurance, if that happens first) to sign up for Part B without a penalty, whether or not you choose COBRA." That last clause is doing a lot of work, and it is easy to read past.

The two clocks that don't line up

Here is the mechanical reason smart, careful people get caught. COBRA is "generally offered for 18 months (36 months in some cases)," per Medicare.gov. Your penalty-free Part B window is 8 months. Both start from roughly the same event — the job ending — and one is more than twice as long as the other.

So the person who plans to "switch to Medicare when COBRA ends" is planning to enroll around month 18, ten months after their protection expired. Nothing warns them at month eight. The COBRA premium keeps drafting, the insurance card still works, and the only thing that changed is invisible.

Run it against a real calendar. Retire on March 31, 2026, elect COBRA in April, turn 65 in August. The Part B special enrollment window closes at the end of November 2026 — while the COBRA policy still has ten months left on it and looks perfectly healthy. Enroll in December instead and you're outside the window; Medicare.gov's answer is that you "wait until January 1 - March 31 to sign up, and your coverage will start the month after you sign up."

Paying for COBRA doesn't mean COBRA pays

This is the part that costs money immediately rather than eventually, and it surprises people who did everything else right. Medicare.gov: "If you have COBRA and you're eligible for Medicare but not enrolled, COBRA may only pay for a small portion of the health care services you get, and you may have to pay most of the costs yourself."

The mechanism is coordination of benefits. Once you're eligible for Medicare, the COBRA plan is generally permitted to pay its share as though Medicare had already paid first — whether or not you ever enrolled. Medicare's phantom payment gets subtracted; nobody actually sends it. You are left holding a full COBRA premium receipt and most of the bill for the same episode of care.

Put a Mesa County number on that. A single inpatient admission runs you into the $1,736 Part A deductible for 2026 before Medicare pays anything — and if you're not enrolled in Part A, that whole layer is simply yours. Medicare.gov's instruction is direct and worth following before you decide anything else: contact your COBRA plan and ask what percent they pay once you're Medicare-eligible. Ask in writing, and keep the answer.

The order of operations almost nobody explains

Now the piece that genuinely rewards knowing the regulation, because the sequence changes the outcome. Federal COBRA rules at 26 CFR §54.4980B-7 let a plan end your continuation coverage on "the date, after the date of the election, upon which the qualified beneficiary first becomes entitled to Medicare benefits." Read the italics as the rule, not as decoration.

The same section says what "entitled" means, and it isn't what people assume: "A qualified beneficiary becomes entitled to Medicare benefits upon the effective date of enrollment in either part A or B, whichever occurs earlier. Thus, merely being eligible to enroll in Medicare does not constitute being entitled to Medicare benefits." Turning 65 does not end your COBRA. Your Part A effective date can.

If you have a reason to want both — a younger spouse on the policy, a treatment mid-course, a dental benefit — the sequence is not a technicality. Getting Medicare in place first is what preserves the COBRA. And there's a related extension worth asking your plan administrator about directly: where the covered employee became Medicare-entitled before the job ended, the regulation runs the family's maximum coverage period to the later of 36 months after that Medicare date or 18 months after the termination. In a household with a five-year age gap, that difference is measured in years of coverage.

What COBRA costs, and the surcharge nobody budgeted for

Two numbers set the price. Federal rules at 26 CFR §54.4980B-8 let a plan charge up to 102 percent of the applicable premium — the full group cost, employer share included, plus a 2% administrative margin — and up to 150 percent during a disability extension. People who only ever saw the payroll-deducted employee share are routinely startled by the real figure.

Then there's the piece that arrives two years late. Severance, a final paid-time-off payout, an accelerated bonus, or a Roth conversion done in the year you left all land in the same modified adjusted gross income that Medicare looks back at to set your premiums. For 2026, CMS puts the first income-related surcharge above $109,000 single and $218,000 joint, which moves the total Part B premium from $202.90 to $284.10 a month. A retirement package can push a one-time spike into a bracket that shows up on your Medicare bill in 2028. If that's your situation, get your tax advisor and your Medicare timing in the same conversation before December — our write-up on Roth conversions and IRMAA timing covers the mechanics, and there's a plain explainer on the 2026 brackets as well.

What the delay actually costs, in 2026 dollars

Medicare.gov's penalty is an extra 10% of the standard premium for each full 12-month period you could have had Part B and didn't. It is not a one-time late fee, and for most people it lasts as long as they have Part B. Applied to the 2026 standard premium of $202.90:

Calculated from Medicare.gov's own method and worked example, applied to the CMS 2026 standard Part B premium. Medicare rounds the result to the nearest ten cents.

Two years late is roughly $40.58 a month on top of the standard premium, forever, and it rises every year the standard premium rises. Over a 25-year retirement that is not a rounding error, and there is no appeal for it — unlike an income-related surcharge, a late-enrollment penalty has no life-changing-event form to file.

The Colorado wrinkle: what if the employer had fewer than 20 people?

Federal COBRA "in general… only applies to employers with 20 or more employees," per Medicare.gov. On the Western Slope, that leaves a lot of people out — the orchards, the shops on Main Street, the two-provider clinics, the outfitters. Colorado fills part of that gap with its own continuation statute.

C.R.S. §10-16-108 gives a right to continue group coverage "for a period of eighteen months after loss of coverage," provided the employee was "continuously covered under the group health benefit plan… for at least six months immediately prior to termination." The election and payment deadlines are short — measured in days, not months — so this is a statute you read the week you leave, not the month after.

And it contains a sentence that matters enormously here, one that has no federal COBRA equivalent: "The employer is not required to offer continuation of coverage to any person if the person is covered by medicare, Title XVIII of the federal 'Social Security Act', or medicaid." In other words, for Colorado small-employer continuation, Medicare coverage can remove the obligation to offer you continuation at all. If you're leaving a small Colorado employer at or near 65, treat Medicare as the plan rather than the fallback, and confirm your specific situation with the Colorado Division of Insurance or your plan administrator — statutes get amended, and this one is theirs to interpret, not mine.

Don't forget the drug side

Part D runs on a separate track with a separate penalty, and COBRA lands differently there. Creditable prescription drug coverage is coverage "expected to pay, on average, at least as much as Medicare drug coverage," and Medicare.gov is clear about whose job it is to tell you: "Your current plan must tell you if your drug coverage is creditable prescription drug coverage."

Some COBRA plans clear that bar; some don't. Don't assume either way — request the notice. If your COBRA drug coverage is creditable, you can generally skip Part D while you hold it, then pick up a plan within 63 days of losing it. Go past 63 days without creditable coverage and the Part D penalty is 1% a month — 12% a year — added to your drug premium for as long as you have it. That letter is worth more than it looks like. File it where you can find it in three years.

Chronic conditions among Mesa County, Colorado adults

Source: CDC PLACES, 2023 — via the Medicare On Main Data Desk. Model-based prevalence among adults, CDC PLACES county data, 2023.

Roughly one in four Mesa County adults lives with high blood pressure (26.6%), and coronary heart disease reaches 5.2%. That's the practical argument against the wait-and-see version of this plan. A gap in coverage is harmless right up until the month it isn't, and the conditions most common here are precisely the ones that produce an unscheduled admission at Intermountain Health St. Mary's Regional Hospital rather than a planned one.

What I'd actually do, in order

• Find your last day of active employment and write it down. Not your COBRA end date. That single date sets your 8 months window, and everything below depends on it.
• Ask the COBRA plan administrator two questions in writing: what percent do you pay once I'm Medicare-eligible, and is the drug coverage creditable? Both answers are theirs to give and yours to keep.
• If you want to hold both, enroll in Medicare first, then elect COBRA — the sequence is what protects the COBRA, per the regulation above.
• Decide Part B on purpose, before the window closes. Not "when COBRA ends." Ten months of daylight between those two dates is where the penalty lives.
• Then pick how you'll cover the 20%. Original Medicare alone leaves the $283 deductible and 20% coinsurance with no annual ceiling — Medigap versus Medicare Advantage lays out the two ways to close it. And mind the other clock: your one-time 6-month Medigap open enrollment starts when you're 65 and enrolled in Part B, and it doesn't come back.
• Bring the severance number to your tax advisor. Not to me — to them, and early enough in the year to matter.

How we know all this: the Medicare On Main Data Desk frames every article with public data — here, Medicare.gov's COBRA page for the 20 or more employees threshold, the 18 months/36 months duration, the "small portion" warning and the 8 months Part B window that applies "whether or not you choose COBRA"; the federal COBRA regulations at 26 CFR §54.4980B-7 for the Medicare-entitlement termination rule, the definition of entitlement as the effective date of Part A or Part B enrollment, and the 36 months-versus-18 months maximum coverage period for other qualified beneficiaries, and §54.4980B-8 for the 102 percent and 150 percent premium ceilings; Colorado Revised Statutes §10-16-108 for the state's eighteen-month continuation right, the six months prior-coverage requirement and the Medicare/Medicaid exclusion; Medicare.gov's late-enrollment-penalty page for the 10%-per-year Part B calculation, its worked 2026 example and the 1% a month Part D penalty; Medicare.gov's creditable-coverage page for the 63 days rule; CMS's 2026 Parts A & B fact sheet, published November 14, 2025, for the $202.90 premium, the $283 deductible, the $1,736 Part A deductible and the 2026 income-related brackets; CMS Hospital General Information for the Mesa County hospital list; and CDC PLACES county data (2023) for Mesa County prevalence. Your own COBRA election dates, premiums and creditable-coverage status come from your former employer's plan administrator — we point you there rather than guess. This is education, not advice; confirm your plan, costs, and eligibility with a licensed agent or Medicare.gov. We take no payment from any carrier to feature a plan.