Medicare · Supporting
Medicare eligibility age: when you can enroll and what happens if you wait
Last reviewed September 6, 20264 min readBy the Goodsurance editorial team Reviewed by the Goodsurance editorial team
Medicare eligibility begins at 65 for most Americans. The enrollment window, called the Initial Enrollment Period (IEP), spans seven months: the three months before your 65th birthday month, the birthday month itself, and the three months that follow. Enrolling in the three months before your birthday month means coverage starts on the first day of your birthday month. Waiting until the fifth, sixth, or seventh month of the IEP delays your start date by one to three months.
The standard eligibility age is 65
If you are already receiving Social Security or Railroad Retirement Board (RRB) benefits at least four months before you turn 65 and you live in the United States, you are automatically enrolled in both Part A (hospital insurance) and Part B (medical insurance). Your Medicare card arrives before your 65th birthday. Part B is not opt-in for this group; it arrives automatically and must be actively refused using the instructions in your Welcome to Medicare package if you do not want it. One geographic carve-out applies: if you live in Puerto Rico, automatic enrollment covers Part A only. You must actively enroll in Part B to obtain that coverage.
If you are not yet collecting Social Security, you sign up through SSA.gov, by phone with Social Security, or at a local Social Security office.
Your 7-month enrollment window
Enrolling in the first 3 months starts coverage on the first day of your birthday month. Waiting until month 5, 6, or 7 delays your start date by 1 to 3 months.
Medicare before 65: disability, ALS, and kidney failure
Age 65 is not the only path in. Three circumstances open Medicare to younger people.
Social Security Disability Insurance (SSDI). According to SSA, Medicare begins after 24 months of receiving SSDI benefits. The clock starts with the first month of payment, not the application date.
Amyotrophic lateral sclerosis (ALS). People diagnosed with ALS receive Medicare beginning with the first month of SSDI eligibility, with no 24-month waiting period.
End-stage renal disease (ESRD). People with kidney failure who require dialysis or a kidney transplant can qualify for Medicare at any age. The specific start month depends on when dialysis begins or when a transplant occurs; Social Security can establish the exact date for your situation.
What happens if you keep working past 65
Many people reach 65 still covered by an employer's group health plan. Medicare provides a Special Enrollment Period (SEP) so you can delay Part B without penalty.
When you or your spouse is actively employed and that employer's group plan covers you, the SEP gives you eight months to sign up for Part B after employment ends or employer coverage ends, whichever comes first. Two limits matter here. First, the eight months begin the day active coverage stops, not the day you learn about it. Second, COBRA and retiree coverage do not count as active employer coverage, so the eight-month SEP clock starts the moment active employment coverage ends, even if you move immediately to COBRA.
Employer size also shapes how claims get paid. With 20 or more employees, the group plan pays primary and Medicare pays secondary. With fewer than 20 employees, Medicare pays primary and the group plan pays secondary. That distinction affects claims processing even before you decide when to enroll.
One more consideration: any Medicare enrollment, including premium-free Part A, ends your eligibility to make new contributions to a Health Savings Account (HSA). Part A can also backdate up to six months. Contributions made during that lookback window could create a tax problem. If you carry an active HSA and are approaching 65, coordinate the timing with your HSA administrator before enrolling.
Penalties for missing your window
Waiting too long without qualifying coverage creates permanent cost increases.
Part B late-enrollment penalty. For each full 12-month period you were eligible for Part B but did not enroll and had no qualifying employer coverage, your Part B premium increases by 10%. The surcharge is permanent and stacks: a two-year gap means a 20% increase added to your premium for life.
Part D late-enrollment penalty. Going 63 or more continuous days without creditable prescription drug coverage after your IEP triggers a Part D penalty. The penalty adds 1% of the national base beneficiary premium for each full month without coverage. In 2026, that base is $38.99 per month. Like the Part B penalty, it is permanent.
Medigap guaranteed-issue window. Medigap (Medicare Supplement) insurance has one guaranteed-issue window: six months, starting the month you are 65 and enrolled in Part B. Outside that window, most states allow insurers to use medical underwriting, which can mean higher premiums or a denial. Some states offer additional protections, organized roughly into a few categories: states with year-round guaranteed issue (such as New York and Connecticut), states that allow plan-to-plan switching (such as Washington), and birthday-rule states including California and Oregon, with New Mexico joining in January 2027. The rules within each category vary considerably. Missing the original six-month window does not close every door, but it narrows your options in most of the country.
Reaching this many continuous days without creditable prescription drug coverage after your enrollment period ends triggers a permanent Part D penalty. The penalty adds 1% of the national base premium for each full month without coverage, and it never goes away.
Who needs to act and when
The simplest summary by situation:
- Turning 65: Watch the seven-month IEP window. Decide before it closes.
- Receiving SSDI: Count 24 months from your first payment month. Enrollment is automatic when you reach that milestone.
- Diagnosed with ALS: Medicare starts with your first month of SSDI eligibility, no waiting period required.
- Kidney failure: Contact Social Security to establish your start date based on dialysis or transplant timing.
- Working past 65 with active employer coverage: Preserve the eight-month SEP, confirm your employer's size and which plan pays primary, and stop HSA contributions before any Part A enrollment.
- Delaying Medigap: Know that the six-month guaranteed-issue window tied to your Part B start date is your broadest access point.
To find out more about coverage options that fit your situation, please contact us to discuss plan options.
Common questions about IRMAA appeals
Quick answers, fast .
Tap any question to expand. Each links to a fuller standalone answer.
Does Medicare pay for hearing aids
Original Medicare does not cover hearing aids or fittings.
Some Medicare Advantage plans may include a hearing benefit, but what they cover varies by plan.
Does Medicare cover ambulance services?
Yes, in limited situations.
Medicare Part B covers emergency ambulance transportation when traveling any other way could endanger your health, taking you to the nearest appropriate hospital or facility. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026. Air ambulance is covered only when ground transport cannot reach you or would take too long. Non-emergency ambulance trips, for example to dialysis, are covered only when a doctor provides a written order stating they are medically necessary. Medicare does not cover ambulance rides taken purely for convenience.
Does Medicare cover skilled nursing facility care?
Yes, on a short-term basis.
Medicare Part A covers skilled nursing facility (SNF) care after a qualifying inpatient hospital stay of at least 3 days, when you need daily skilled care like nursing or therapy. In 2026 you pay $0 for days 1 through 20 of each benefit period, $217 per day for days 21 through 100, and all costs after day 100. Coverage is for skilled care while you recover, not for long-term or custodial care (help with daily activities like bathing or dressing), which Medicare does not cover. Long-term nursing home care is generally paid through Medicaid or private funds.
Does Medicare cover physical therapy?
Yes.
Medicare Part B covers outpatient physical therapy that is medically necessary to treat your condition. You pay 20% of the Medicare-approved amount after the yearly Part B deductible ($283 in 2026). There is no longer a hard dollar cap on therapy, but once your physical and speech therapy together pass $2,480 in 2026, your therapist must add a note (called a KX modifier) confirming you still need care. Claims above $3,000 may be reviewed for medical necessity. Part A covers physical therapy you receive as a hospital inpatient or in a skilled nursing facility. A doctor or therapist must set up and regularly review your plan of care.
Does Medicare cover mental health services?
Yes.
Medicare covers mental health care across its parts in 2026. Part B covers outpatient services like therapy, counseling, and visits with psychiatrists, psychologists, and clinical social workers, and since 2024 it also covers marriage and family therapists and mental health counselors. You pay 20% of the Medicare-approved amount after the $283 deductible, and one depression screening each year is free. Part A covers inpatient mental health care, with a lifetime limit of 190 days in a freestanding psychiatric hospital. Part D covers most mental health medications. Many of these services are also available by telehealth, and Medicare Advantage plans cover at least the same benefits.
Does Medicare cover chiropractic care?
Partly.
Medicare Part B covers one specific chiropractic service: manual manipulation of the spine to correct a subluxation (when one or more bones of the spine are out of position) that a doctor confirms is medically necessary. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026. Medicare does not cover other services a chiropractor might offer, such as X-rays, massage therapy, acupuncture, or routine wellness visits, so you would pay the full cost for those. Some Medicare Advantage plans include extra chiropractic or wellness benefits beyond this.
Does Medicare cover home health care?
Yes, when you qualify.
Medicare Parts A and B cover home health care if a doctor certifies that you are homebound (leaving home takes a major effort) and need part-time skilled care, such as skilled nursing, physical therapy, occupational therapy, or speech therapy. A Medicare-certified home health agency must provide the care under a plan your doctor reviews. You pay $0 for covered home health visits in 2026, and 20% for any durable medical equipment. Medicare does not cover 24-hour home care, meal delivery, or homemaker services like cleaning when that is the only care you need.
Does Medicare cover vision care?
Mostly no for routine care.
In 2026, Original Medicare does not cover routine eye exams for glasses or contact lenses, and it does not pay for the glasses or contacts themselves. It does cover some medical eye care: yearly glaucoma screenings for people at high risk, diabetic retinopathy exams, treatment for eye diseases, and cataract surgery (including one pair of standard glasses or contacts afterward). For those covered services you pay 20% after the $283 Part B deductible. Many Medicare Advantage plans add a routine vision benefit covering eye exams and an allowance for glasses.
Does Medicare cover hearing aids?
Original Medicare does not cover hearing aids or the exams used to fit them.
Some Medicare Advantage plans include a hearing benefit, but coverage varies by plan.
Does Medicare cover diabetes supplies and testing?
Yes.
In 2026 Medicare covers most diabetes care across two parts. Part B (outpatient care and equipment) covers blood sugar monitors, test strips, lancets, and continuous glucose monitors (CGMs) as durable medical equipment, plus diabetes screenings and a self-management training program. You pay 20% of the Medicare-approved amount after the $283 Part B deductible. Part D (drug coverage) covers insulin and related supplies like syringes, and in 2026 your insulin is capped at $35 for a month's supply. If you have a Medicare Advantage plan, it covers at least the same diabetes benefits, sometimes with added extras.
Does Medicare cover durable medical equipment?
Yes.
Medicare Part B covers durable medical equipment (DME): reusable medical gear your doctor prescribes for use at home, such as wheelchairs, walkers, hospital beds, oxygen equipment, CPAP machines, and blood sugar monitors. You pay 20% of the Medicare-approved amount after the $283 Part B deductible in 2026, and Medicare pays the other 80%. To be covered, the item must be ordered by a Medicare-enrolled doctor and supplied by a Medicare-enrolled supplier, and some items are rented rather than bought. Equipment meant mainly for use outside the home, or only for comfort or convenience, is not covered.
Which is better, Medigap or Medicare Advantage?
Neither is better for everyone; they suit different needs.
Medigap (also called Medicare Supplement, a private policy that pairs with Original Medicare) lets you see any doctor nationwide who accepts Medicare with no network and very predictable out-of-pocket costs, but you pay a monthly Medigap premium and add a separate Part D drug plan. Medicare Advantage (Part C, your Medicare benefits through a private plan) often has a lower or $0 plan premium, bundles drug coverage and extras like dental and vision, and caps your yearly out-of-pocket costs, but uses provider networks and may require prior approval. People who travel, want maximum doctor freedom, and prefer steady costs often lean Medigap; people who want low premiums, extras, and a network they are comfortable with often lean Medicare Advantage. With both, you still pay the Part B premium ($202.90 per month in 2026). To find out which fits your situation, reach out to a licensed Goodsurance advisor at 1-888-301-8091 (TTY 711), Mon to Fri 8 am to 5 pm PT.
References
- Medicare basics: get started with MedicareCovers the Initial Enrollment Period, automatic enrollment rules, Special Enrollment Periods, and late-enrollment penalties for Part B, Part D, and Medigap.
- SSA Handbook section 2508: Medicare for disabled beneficiariesDetails the 24-month SSDI waiting period and the separate timing rules for ALS and ESRD.