Medicare Part B costs $185/month in 2026. Miss your 7-month Initial Enrollment Period and you face permanent premium penalties per year late.
Medicare is the federal health insurance program for people 65 and older. Part A (hospital) is free for most people who worked 40+ quarters; Part B (medical) costs $185/month in 2026. You have a 7-month Initial Enrollment Period around your 65th birthday to sign up without penalty. If you have active employer coverage, you can delay without penalty — but COBRA and retiree coverage don't count. Miss your window without a valid reason and Part B charges a permanent 10% premium penalty per year of delay.
Medicare is the federal health insurance program for people 65 and older — and for certain younger individuals with disabilities or end-stage renal disease. Understanding enrollment rules before you turn 65 can prevent costly, permanent premium penalties.
Medicare has four parts, each covering a different category of care:
Most people start with Original Medicare (Parts A and B) and then decide separately whether to add a Medicare Advantage plan or pair Original Medicare with a Medigap supplement and standalone Part D drug plan. For a primer on Medigap plan types, see What Is a Medicare Supplement (Medigap) Plan?.
Premium-free Part A is available to anyone who — or whose spouse — worked and paid Medicare taxes for at least 40 quarters (10 years) in the U.S. Per Medicare.gov, the large majority of new enrollees at 65 qualify.
People who worked 30–39 quarters can still enroll in Part A but pay a reduced monthly premium; fewer than 30 quarters results in a higher rate. CMS publishes the current Part A premium amounts each fall for the following year.
Part A carries a per-benefit-period hospital deductible — $1,736 in 2026 — plus daily coinsurance for stays longer than 60 days. There is no annual cap on Part A deductibles because each "benefit period" resets 60 days after discharge.
Part B is not free. The standard monthly premium is $185.00 in 2026, per the CMS 2026 Medicare Parts B Premiums and Deductibles fact sheet. The annual Part B deductible is $283. After the deductible, Original Medicare pays 80% of most approved outpatient services; you pay the remaining 20% — with no annual out-of-pocket ceiling under Original Medicare alone.
Higher-income beneficiaries pay an Income-Related Monthly Adjustment Amount (IRMAA): an additional monthly premium based on the modified adjusted gross income reported on your tax return two years prior. CMS adjusts IRMAA thresholds annually — verify current brackets directly with CMS. If your income dropped significantly since the base year (retirement is a common trigger), you can request a new initial determination using a more recent tax return.
The Initial Enrollment Period (IEP) is a 7-month window:
1. The 3 months before the month you turn 65 2. The month you turn 65 3. The 3 months after the month you turn 65
Enrolling during the 3 months before your birthday month gives you coverage starting the month you turn 65. Enrolling in your birthday month or later delays your coverage start date by 1–3 months. Per SSA.gov, you can apply for Medicare online through the Social Security Administration even if you have not yet started claiming Social Security retirement benefits.
If you are covered by active employer-sponsored insurance from your own current job or a spouse's current job at 65, you can delay Part B without facing the late-enrollment penalty. When that active coverage ends, you qualify for a Special Enrollment Period (SEP): an 8-month window beginning the month after your employment or employer coverage ends, whichever comes first.
Two rules that trip up many people:
For self-employed business owners managing their own health coverage as they approach 65, see Health Insurance for Self-Employed Business Owners in 2026 for how individual-market and ACA plans interact with Medicare timing.
If you miss both the IEP and a valid SEP, you can still enroll during the General Enrollment Period (GEP): January 1 through March 31 of each year. Coverage under GEP starts July 1.
The trade-off: enrolling via GEP typically triggers the late-enrollment penalty unless you have a valid exception.
Part B late penalty: 10% is added to the standard monthly Part B premium for each full 12-month period you were eligible but did not enroll. This surcharge is permanent — it applies for as long as you have Part B. A 2-year delay adds 20% to every monthly premium for life; a 3-year delay adds 30%. On a $185/month base premium, that 30% penalty amounts to an extra $55.50 every month, indefinitely.
Part D late penalty: 1% of the national base beneficiary premium multiplied by the number of months you went without creditable prescription drug coverage. This also applies permanently and is recalculated each year as the base premium changes.
Part A penalty (for those who owe premiums): If you don't qualify for premium-free Part A and don't enroll when first eligible, your Part A premium increases by 10% for twice the number of years you delayed.
IRMAA applies to Part B and Part D for beneficiaries whose modified adjusted gross income exceeds set thresholds, using income from two years prior. Because the surcharge is calculated from a prior year's income, a significant income drop — retirement, sale of a business, or a one-time capital event — can create an IRMAA bill based on income you no longer have. You can file for a Life-Changing Event appeal with SSA to use a more recent income estimate.
Medicare and Social Security are independent programs. If you are already receiving Social Security when you turn 65, per SSA.gov you are automatically enrolled in Part A and Part B — your Medicare card arrives approximately 3 months before your 65th birthday. If you have not started Social Security, you must actively sign up for Medicare.
When you claim Social Security — at 62, at Full Retirement Age (67 for those born in 1960 or later), or at 70 — does not affect your Medicare enrollment window. For a breakdown of that separate decision, see When to Claim Social Security: Age 62, Full Retirement Age, or 70?.
---
This content is educational and does not constitute health insurance or financial planning advice. Medicare premiums, enrollment periods, and penalty rules are subject to annual change. Verify current figures at medicare.gov and cms.gov before making enrollment decisions.
Your Initial Enrollment Period (IEP) is a 7-month window: 3 months before the month you turn 65, your birthday month, and 3 months after. Per Medicare.gov, enrolling in the 3 months before your birthday month gives you coverage starting the month you turn 65. Enrolling during or after your birthday month shifts the coverage start date 1–3 months later, depending on when you sign up.
Yes — if you have active employer-sponsored health coverage from your own job or a spouse's current job, you can delay Part B without penalty. You qualify for a Special Enrollment Period: an 8-month window starting the month after your employment or employer coverage ends. Per Medicare.gov, COBRA continuation coverage and retiree health insurance do not count as active employer coverage — the Special Enrollment Period clock starts when active employer coverage ends, not when COBRA ends.
The Part B late penalty is 10% of the standard monthly premium for each full 12-month period you were eligible but did not enroll. Per Medicare.gov, this surcharge is permanent — it is added to your Part B premium for as long as you have coverage. A 3-year delay results in a 30% permanent premium increase on top of the standard rate ($185/month in 2026).
The standard monthly premium is $185.00 in 2026, per the CMS 2026 Medicare cost fact sheet. The annual Part B deductible is $283. After the deductible, Original Medicare pays 80% of covered outpatient services; you pay 20% with no annual cap. Higher-income beneficiaries pay an IRMAA surcharge above the standard premium — CMS publishes current income thresholds annually.
No. Medicare and Social Security are separate programs with independent rules. If you are already receiving Social Security when you turn 65, per SSA.gov you are automatically enrolled in Part A and Part B — no action needed. If you have not yet claimed Social Security, you must actively apply for Medicare through SSA. Delaying or accelerating Social Security does not change your Medicare enrollment window.