Medicare Part B in California costs $202.90 per month in 2026 with a $283 annual deductible, covers outpatient medical care and preventive services, and must be enrolled in during a specific seven-month window around your 65th birthday unless you have qualifying employer coverage. Because Part B is federal, the coverage rules are the same as anywhere else in the country. What California adds is some of the most generous state assistance for residents who need help paying the premium, including Medicare Savings Programs with no asset limit.
What Part B Covers
Part B handles the outpatient side of Medicare. Part A pays for inpatient hospital stays, skilled nursing, and hospice; Part B pays for the doctors, tests, equipment, and screenings you receive outside a hospital admission.1Medicare.gov. Parts of Medicare That includes physician and specialist visits, outpatient surgery, lab work and imaging, durable medical equipment such as wheelchairs and oxygen, ambulance services, mental health and substance use treatment, and a limited set of outpatient drugs.2Medicare.gov. What Part B Covers
Preventive services are covered at no cost when you see a provider who accepts Medicare assignment. These include the annual wellness visit, cardiovascular and diabetes screenings, mammograms, and colorectal and prostate cancer screenings.3HHS.gov. What Does Medicare Part B of Medicare (Medical Insurance) Cover The wellness visit is worth using every year since it costs you nothing.
What Part B Does Not Cover
Original Medicare has real gaps. Routine dental care (cleanings, fillings, dentures), eye exams for prescription glasses, hearing aids and the exams to fit them, and long-term custodial care are all excluded.4Medicare. What’s Not Covered If you need these regularly, your options are a Medicare Advantage plan that bundles them in, a standalone dental or vision plan, or Medi-Cal if your income qualifies.
What Part B Costs in 2026
The standard monthly premium is $202.90. Before Medicare begins paying its 80% share, you need to meet the annual deductible of $283.5Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles After the deductible, you owe 20% coinsurance on most covered services, and Original Medicare has no annual out-of-pocket cap. That uncapped exposure is the main reason many California beneficiaries also carry a Medigap policy or choose Medicare Advantage.
Higher Premiums for Higher Incomes (IRMAA)
Higher earners pay a surcharge called the Income-Related Monthly Adjustment Amount. Medicare uses the modified adjusted gross income from the tax return filed two years earlier, so your 2024 return sets your 2026 premium. The surcharge begins once income passes $109,000 for individual filers or $218,000 for married couples filing jointly.5Centers for Medicare & Medicaid Services. 2026 Medicare Parts A and B Premiums and Deductibles
- Up to $109,000 individual / $218,000 joint: $202.90 per month
- $109,001–$137,000 / $218,001–$274,000: $284.10
- $137,001–$171,000 / $274,001–$342,000: $405.80
- $171,001–$205,000 / $342,001–$410,000: $527.50
- $205,001–$499,999 / $410,001–$749,999: $649.20
- $500,000 or more / $750,000 or more: $689.90
If a major life event has cut your income since the tax year Medicare is using, you can ask Social Security to recalculate your IRMAA by filing Form SSA-44. Qualifying events include marriage, divorce, the death of a spouse, stopping work or reducing hours, loss of income-producing property through disaster or fraud, loss of pension income, and employer settlement payments due to bankruptcy.6Social Security Administration. Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event (Form SSA-44) If you retired in 2025 and your income dropped, there is no reason to keep paying a surcharge based on your peak earning years.
When to Enroll
Part B enrollment follows strict timing. Missing your window can leave you uninsured for months and trigger a permanent penalty.
Initial Enrollment Period
Your first chance to enroll is a seven-month window around your 65th birthday: the three months before your birthday month, the birthday month, and the three months after.7Medicare.gov. When Does Medicare Coverage Start Signing up in the first three months gives you the earliest possible coverage start date. Waiting until the months after your birthday delays when coverage begins.
Special Enrollment Period
If you keep working past 65 and remain covered by an employer group health plan based on current employment, you can delay Part B without penalty. You can enroll any time while that coverage is active, or during the eight months after the employment ends or the group coverage ends, whichever comes first.8Centers for Medicare & Medicaid Services. Original Medicare (Part A and B) Eligibility and Enrollment Pay attention to the “whichever comes first” part if your coverage ends before your last day of work.
The COBRA Trap
COBRA continuation coverage does not count as employer group coverage for the Part B Special Enrollment Period. Your eight-month SEP clock starts when you stop working or lose your employer plan, whether or not you elect COBRA afterward.9Medicare.gov. COBRA Coverage If you lean on COBRA for 18 months thinking it protects your Medicare rights, you will burn through the entire SEP and end up with both a coverage gap and a permanent penalty. If you’re leaving an employer at 65 or older, enroll in Part B within eight months of your last day of work, even if you take COBRA in the meantime.
General Enrollment Period
If you miss both the IEP and any SEP you qualified for, the General Enrollment Period runs January 1 through March 31 each year.8Centers for Medicare & Medicaid Services. Original Medicare (Part A and B) Eligibility and Enrollment Coverage starts the month after you sign up.7Medicare.gov. When Does Medicare Coverage Start By the time you use the GEP, you’ve likely gone months without coverage and will almost certainly owe the late enrollment penalty.
The Late Enrollment Penalty
Skipping Part B when you’re first eligible without qualifying coverage adds 10% to your monthly premium for every full 12-month period you could have been enrolled but weren’t.10Medicare. Avoid Late Enrollment Penalties Three years late means a 30% permanent surcharge. On the 2026 standard premium, that’s roughly $61 extra every month for as long as you carry Part B. It isn’t a one-time fee.
How to Sign Up
If you already receive Social Security benefits, you’ll be enrolled in Part A and Part B automatically when you become eligible, and your card will arrive in the mail before coverage begins. You can decline Part B if you don’t want to pay the premium.11Social Security Administration. How Do I Sign Up for Medicare
If you’re not yet collecting Social Security, you need to sign up actively. The fastest route is the online application on Social Security’s website. You can also call 1-800-772-1213 or visit your local office.12Medicare.gov. How Do I Sign Up for Medicare
Enrolling under a Special Enrollment Period takes two forms: Form CMS-40B (Application for Enrollment in Medicare Part B) and Form CMS-L564 (Request for Employment Information), with your employer completing Section B of the L564 to confirm your group plan and employment dates.13Centers for Medicare & Medicaid Services. CMS-L564 Request for Employment Information Submit both to your local Social Security office by mail or fax. Without the employer verification, Social Security may treat your enrollment as late and apply the penalty.
California Programs That Pay Your Part B Premium
California residents with limited income may qualify for Medicare Savings Programs run through Medi-Cal, the state’s Medicaid program. California has eliminated asset limits for these programs, so eligibility depends on income alone.14DHCS – CA.gov. Medicare Savings Programs in California The 2025 monthly income limits listed below are the most recent published; 2026 figures had not been released at the time of writing.
- Qualified Medicare Beneficiary (QMB) covers Part A and Part B premiums, deductibles, and coinsurance. 2025 income limit: $1,305 individual, $1,763 couple.
- Specified Low-Income Medicare Beneficiary (SLMB) covers your Part B premium. 2025 income limit: $1,566 individual, $2,116 couple.
- Qualifying Individual (QI) covers your Part B premium; you cannot also receive full Medi-Cal. 2025 income limit: $1,762 individual, $2,381 couple.
- Qualified Disabled and Working Individual (QDWI) covers your Part A premium if you lost premium-free Part A after returning to work. 2025 income limit: $2,610 individual, $3,526 couple.
California applies certain deductions during the eligibility determination, so apply even if your income is slightly above the listed amounts.14DHCS – CA.gov. Medicare Savings Programs in California Apply through your county social services office in person, by phone, or by mailing Form MC 14A. The Medi-Cal Helpline at (800) 541-5555 can direct you to your county office. Qualifying for QMB also automatically enrolls you in Medicare’s Extra Help program for prescription drug costs.
Filling the 20% Gap
Because Original Medicare has no annual out-of-pocket cap, a single expensive surgery or cancer treatment can produce enormous bills under the 20% coinsurance. Two options close the gap.
Medicare Supplement Insurance (Medigap) policies sold by private insurers cover some or all of the costs Original Medicare leaves behind, including the Part B coinsurance and deductible. Federal law gives you a six-month Medigap Open Enrollment Period that starts the first month you have Part B and are 65 or older. During that window, insurers cannot deny you coverage or charge more based on health conditions.15Medicare.gov. Get Ready to Buy After it closes, insurers in most situations can use medical underwriting. The best time to buy a Medigap policy in California is when you first enroll in Part B at 65.
Medicare Advantage (Part C) is the other route. These private plans must cover everything Original Medicare covers and typically add dental, vision, hearing, and prescription drugs, but most require in-network providers and may require prior authorization.16Medicare.gov. Compare Original Medicare and Medicare Advantage You still pay the Part B premium even if you join a Medicare Advantage plan. Some plans offer a partial Part B premium giveback. California’s Advantage market is competitive, and plan networks, costs, and benefits change every year, so comparing plans during the fall Open Enrollment Period (October 15 through December 7) is worth the effort.