Coverage decision · 2026
Medicare vs ACA
Compare Medicare and Marketplace paths using your age, employer size, coverage type, Part A work credits, and HSA status. The result shows a path, the reasoning, costs, and the enrollment windows to calendar.
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| 20-employee rule | 20 employeesActive employer coverage at or above this size generally pays first. |
|---|---|
| Part B standard premium | $202.90Monthly standard amount before IRMAA. |
| Part A full premium | $565.00Applies with fewer than 30 work credits. |
| Part A reduced premium | $311.00Applies with 30 to 39 work credits. |
| Special Enrollment Period | 8 monthsUsually after active employer coverage ends. |
| HSA stop date | 6 monthsBefore Part A begins, because Part A can be backdated. |
Your result
Recommended path
You can generally delay Part B. Part A status Premium-free. Annual Medicare premium estimate $2,434.80.
At age 65 with active employer coverage, the calculator recommends: You can generally delay Part B. Part A is premium-free, and the annual Medicare premium estimate is $2,434.80.
Why this path
- Your current employer has 20 or more employees, so the group health plan generally pays first.
- You can usually delay Part B without a penalty while you have creditable coverage.
Check these warnings
- Marketplace premium tax credits generally end once you are eligible for premium-free Part A.
- You have eight months after active employer coverage ends to sign up for Part B without a penalty.
Deadline timeline
| Window | Dates | What to do |
|---|---|---|
| Initial Enrollment Period | March 1, 2026 to September 30, 2026 | Sign up for Part A and Part B if you are not delaying. |
| General Enrollment Period | January 1 through March 31 each year | Use this if you missed your first chance and do not qualify for a SEP. |
Cost view
At the 2026 standard premium, Part B costs $2434.80 a year. Part A is premium-free. A Marketplace benchmark premium is not included.
This estimate does not include a Marketplace benchmark premium, a Medicare Advantage plan, a Medigap policy, or Part D. Compare those costs separately before choosing a path.
Show the math
- Part B: $202.90 × 12 = $2,434.80.
- Part A: premium-free, so the annual amount is $0.00.
- Annual Medicare premium estimate: $2,434.80 + $0.00 = $2,434.80.
- Employer size rule: 25 employees. The comparison uses the 20-employee rule where active coverage applies.
What to do next
- Confirm the employer factsAsk HR for the employer size, whether the coverage is creditable, and the exact date active coverage ends. Keep the written answer.
- Protect the Part B windowIf you can delay Part B, calendar the eight-month Special Enrollment Period after active coverage ends. If you cannot delay, enroll during your Initial Enrollment Period.
- Handle Part A and the HSAIf Part A is not premium-free, compare the full Part A and Part B cost with a Marketplace plan. If you contribute to an HSA, stop contributions six months before Part A begins.
Scenario compare
Change one fact to see how the answer moves. The alternate column uses the same rules and the same sources.
| Result | Current | Alternate |
|---|---|---|
| Recommended path | You can generally delay Part B | Compare ACA Marketplace and employer coverage |
| Part A status | Premium-free | Premium-free |
| Annual Medicare estimate | $2,434.80 | $2,434.80 |
| ACA subsidy signal | Marketplace subsidies generally end | Employer coverage may block subsidies |
Deadline and timing
The Initial Enrollment Period is seven months around the month you turn 65. The usual employment Special Enrollment Period is eight months after active coverage ends. The General Enrollment Period is January 1 through March 31 each year.
COBRA and retiree coverage generally do not extend the Part B Special Enrollment Period. Confirm the coverage type with HR before you delay.
A result can be right for the inputs and still be wrong for your state or tax household.
Report an error in this calculatorMedicare 20 employee rule
With active employer coverage from an employer with 20 or more employees, the group health plan generally pays first for a worker age 65 or older. That rule is why many people can delay Part B without a penalty.
With fewer than 20 employees, Medicare generally pays first. The employer count can include full-time equivalents, so ask HR for the official count instead of guessing from the number of people in your department.
Should I take Medicare or Marketplace at 65
At 65, start with whether you have premium-free Part A. If you do, the Marketplace subsidy path generally ends. Compare your active employer plan with Medicare, and choose based on the premium, the network, the drug coverage, and the enrollment risk.
If you do not have premium-free Part A, compare the full Part A and Part B cost with a Marketplace plan and any premium tax credit. The calculator shows the Medicare premium side; it does not invent a Marketplace benchmark premium.
ACA subsidies end when eligible for Part A
Marketplace premium tax credits generally end once you are eligible for premium-free Part A. That can happen even if you delay Part B. Being eligible for premium-free Part A is the key fact, not whether you have enrolled yet.
If Part A is not premium-free, the Marketplace may still be an option. Check the income rules and the current 400% federal poverty level cliff before you rely on a subsidy.
No premium free Part A what to do
If you do not have premium-free Part A, get your work credits from Social Security and ask whether you qualify for a reduced premium with 30 to 39 credits. Then compare the full annual Medicare premium with a Marketplace plan and any subsidy.
In the worked example below, a person with 35 credits uses the reduced Part A premium, not the full premium. The exact amount depends on the current Part A table.
Working past 65
If you keep working past 65, the 20-employee rule, creditable coverage, and the type of coverage decide whether you can delay Part B. Active coverage is different from COBRA and retiree coverage.
If you contribute to an HSA, stop contributions six months before Part A begins. Part A can be backdated, and an HSA contribution after Medicare starts can create a tax issue. The calculator shows the enrollment windows once you enter the month you turn 65 and the month coverage ends.
What changed for 2026 compared with 2025
| Rule | 2025 | 2026 |
|---|---|---|
| Part B standard premiumMonthly standard amount before IRMAA. | $185.00 | $202.90 |
| Annual Part B standard costUsed in the Medicare cost estimate. | $2,220.00 | $2,434.80 |
| Part A full premiumApplies with fewer than 30 work credits. | $518.00 | $565.00 |
| Part A reduced premiumApplies with 30 to 39 work credits. | $285.00 | $311.00 |
| Affordability percentageUsed for the employer affordability test, not this decision directly. | 9.02% | 9.96% |
| Enhanced Marketplace subsidiesCheck the current Marketplace rules before applying. | Enhanced subsidies available | Expired after 2025; 400% FPL cliff generally applies |
Worked example
A 66-year-old has active coverage from an employer with 25 employees, creditable coverage, and 40 work credits. The employer plan pays first, so Part B can generally be delayed. Part A is premium-free, which generally ends the Marketplace subsidy path.
| Recommended path | You can generally delay Part B |
|---|---|
| Part A status | Premium-free |
| Annual Part B | $2,434.80 |
| Annual Part A | $0.00 |
| Annual Medicare premium estimate | $2,434.80 |
| ACA subsidy signal | Marketplace subsidies generally end |
With 35 work credits and no premium-free Part A, the same person would use the reduced Part A premium and compare $6,166.80 a year in Medicare premiums with a Marketplace plan.
MedicareClear is independent. We do not sell plans, rank carriers, or claim an official connection to Medicare.gov or any government agency.
Three honest caveats
- The 20-employee rule can count full-time equivalents, and the plan's creditable-coverage notice controls. Ask HR for both facts in writing.
- This calculator does not include a Marketplace benchmark premium, a Medigap policy, a Medicare Advantage plan, or Part D. Compare the full cost of each path, not just the premium shown here.
- COBRA and retiree coverage are not active employer coverage for the Part B Special Enrollment Period. Do not delay Part B based only on the name of the coverage.
Frequently asked questions
Medicare vs ACA subsidies
Eligibility for premium-free Part A generally ends Marketplace premium tax credits. At 65, if you have premium-free Part A, the Marketplace subsidy path usually closes even if you delay Part B. Without premium-free Part A, the Marketplace may still be an option.
Can I delay Medicare if I have employer coverage?
You can usually delay Part B without a penalty if you have active employer coverage from an employer with 20 or more employees and the coverage is creditable. You generally have eight months after that coverage ends to enroll.
Does COBRA count as active employer coverage?
COBRA generally does not count as active employer coverage for the Part B Special Enrollment Period. Retiree coverage is also different. Do not delay Part B only because you have COBRA; confirm the rule with Social Security.
What happens if I do not have premium-free Part A?
You may need to compare the full Part A and Part B premium with a Marketplace plan and any premium tax credit. With 30 to 39 work credits, Part A can use a reduced premium rather than the full premium.
When should I stop HSA contributions?
Stop HSA contributions six months before Medicare Part A begins. Part A can be backdated up to six months, so a contribution after that point can create a tax problem.
What if my employer has fewer than 20 employees?
With active coverage from an employer with fewer than 20 employees, Medicare generally pays first. Enrolling in Part B usually avoids gaps and penalty risk. Ask HR and Social Security to confirm the employer size rule for your plan.
Related help
Source table
| Figure | Value used | Official source |
|---|---|---|
| 20-employee rule | 20 or more employees | Medicare.gov coordination of benefitsChecked |
| Part B standard premium | $202.90 | CMS Part B premium fact sheetChecked |
| Part A premiums | $311.00 reduced / $565.00 full | CMS Part B premium fact sheetChecked |
| Special Enrollment Period | 8 months | Medicare.gov sign-up rulesChecked |
| HSA six-month rule | 6 months before Part A | Medicare.gov sign-up rulesChecked |
| Marketplace subsidy status | Enhanced subsidies expired; 400% FPL cliff generally applies | Congressional Research ServiceChecked |
Cite this page
If you cite this page, use the reference below. It shows the date the figures were last checked so readers can judge whether they are current.
MedicareClear. “Medicare vs ACA.” Figures checked October 28, 2026. https://medicareclear.top/calculators/medicare-vs-aca
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MedicareClear is independent and is not connected to Medicare.gov, Social Security, HealthCare.gov, or any government agency. This page is educational and does not provide legal, tax, or insurance advice. Confirm your work credits, employer size, and coverage dates with the official sources before you act.
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