Reviewed for accuracy by Lauri Middleton, RN, MSN, licensed Medicare agentReviewed for clarity by Karen OrillaMeet our reviewers →
California Medicare Guidance
California rulebook
Every rule this site relies on, in plain words, with its source and the date it was last checked. Rules are stated generally; the agency named on each card decides how it applies to you.
Timing
Your first enrollment window lasts seven months
The Initial Enrollment Period starts three months before the month you turn 65, includes your birthday month, and ends three months after it. Signing up in the first three months usually means coverage starts the month you turn 65.
Who this is for
People becoming eligible for Medicare because they are turning 65.
What changes it
- If your birthday is on the first of the month, the whole window moves one month earlier.
- If you have coverage from current work, you may be able to enroll later without a penalty.
The question that settles it
“What are my exact Part A and Part B enrollment dates?” — Social Security, 1-800-772-1213.
A birthday on the first moves everything a month earlier
Medicare treats someone born on the first day of a month as reaching 65 in the previous month. Their window opens and closes one month earlier, and coverage can begin one month earlier.
Who this is for
Anyone whose birthday falls on the first of any month.
What changes it
- This only changes timing; it does not change who is eligible.
The question that settles it
“My birthday is on the first. Which month does Medicare count as my 65th?” — Social Security.
If you missed your window, there is a yearly catch-up period
The General Enrollment Period runs January 1 through March 31 every year. If you sign up then, coverage starts the month after you sign up. A late-enrollment penalty may still apply.
Who this is for
People who did not sign up during their first window and do not qualify for a Special Enrollment Period.
What changes it
- A Special Enrollment Period, if one applies, is usually the better route because it may avoid the penalty.
The question that settles it
“Do I qualify for a Special Enrollment Period, or do I need to wait for the General Enrollment Period?” — Social Security.
Penalties
Signing up late for Part B usually costs extra for life
If you sign up for Part B after your first window ends and did not have coverage from current work in between, Medicare generally adds 10% to your Part B premium for every full 12 months you could have had Part B but did not — and the extra amount usually lasts as long as you have Part B.
Who this is for
People who delay Part B without qualifying job-based coverage.
What changes it
- Coverage from your own or a spouse’s current employer generally lets you delay without a penalty.
- COBRA and retiree coverage usually do not count as current-employment coverage.
The question that settles it
“Will I owe a Part B late-enrollment penalty, and how is it calculated for me?” — Social Security.
Drug coverage has its own, separate penalty
If you go 63 days or more without Medicare drug coverage or other creditable drug coverage after your first window, Medicare generally adds a monthly amount to your Part D premium for as long as you have drug coverage. It is based on how many months you went without.
Who this is for
Anyone with Medicare who goes without creditable drug coverage.
What changes it
- Employer, union, VA and some other drug coverage counts as creditable — your plan must tell you in writing each year.
- People who receive Extra Help do not pay this penalty.
The question that settles it
“Is my current drug coverage creditable? Please give me that in writing.” — your employer or plan.
Working past 65
After job coverage ends you have 8 months for Part B
If you delayed Part B because you or your spouse had coverage from current work, you get a Special Enrollment Period: 8 months starting the month after the job or the coverage ends, whichever comes first. Signing up in that time avoids the Part B penalty.
Who this is for
People 65+ who kept coverage from their own or a spouse’s current employer.
What changes it
- COBRA and retiree coverage do not start or extend this period.
The question that settles it
“My job coverage ends on [date]. When does my 8-month Part B Special Enrollment Period end?” — Social Security.
Source: Social Security Administration — Sign up for Part B only ↗
Drug coverage has a much shorter clock: about two months
When creditable drug coverage from work ends, you generally have two months to join a Medicare drug plan without a penalty. This clock is separate from — and much shorter than — the 8-month Part B clock.
Who this is for
People leaving job-based drug coverage after 65.
What changes it
- If the work coverage was not creditable, the penalty clock may already be running.
The question that settles it
“When exactly does my drug coverage end, and was it creditable?” — your benefits administrator, in writing.
Employer size decides who pays first — and whether delaying Part B is safe
If the employer has 20 or more employees, the job plan usually pays first and Medicare second — so many people safely delay Part B. If the employer has fewer than 20 employees, Medicare usually pays first, and a job plan may pay very little until you have Part B. In that case delaying Part B can leave large bills unpaid.
Who this is for
People 65+ with coverage from their own or a spouse’s current employer.
What changes it
- The count is the employer’s total employees, not the number on the plan.
- Different rules apply for disability-based Medicare (the threshold is 100 employees).
The question that settles it
“How many employees does the company have in total, and does our plan pay first or second for someone 65 or older?” — your benefits administrator, in writing.
“Creditable” means your drug coverage is at least as good as Medicare’s
Your employer or plan must tell you in writing, every year, whether its drug coverage is creditable. Keep that notice. It is what proves later that you can join a Medicare drug plan without a penalty.
Who this is for
Anyone delaying Medicare drug coverage because of other coverage.
What changes it
- Medical coverage being good does not make the drug coverage creditable; they are judged separately.
The question that settles it
“Please send me this year’s creditable coverage notice.” — your benefits administrator.
HSA
Medicare and HSA contributions do not mix — and Part A can start six months back
Once any part of Medicare starts, you generally may not contribute to a Health Savings Account. If you apply for Medicare after 65, Part A is usually backdated up to six months (but not before the month you turned 65). Many people stop HSA contributions six months before applying so the backdated months do not create excess contributions.
Who this is for
People with an HSA who are still working past 65.
What changes it
- You can still spend existing HSA money; only new contributions stop.
- Taking Social Security benefits enrolls you in Part A automatically.
The question that settles it
“Given when I plan to apply, when should my HSA contributions stop?” — your benefits administrator or tax adviser.
Source: Internal Revenue Service — Publication 969 — Health Savings Accounts ↗
Every year
October 15 to December 7: the yearly window to change plans
Every year during Open Enrollment you can switch between Original Medicare and Medicare Advantage, change Medicare Advantage plans, or join, drop or change a drug plan. Changes take effect January 1.
Who this is for
Everyone who already has Medicare.
What changes it
- Switching from Medicare Advantage back to Original Medicare does not by itself guarantee a Medigap policy; see the Medigap rule.
The question that settles it
“If I make this change by December 7, exactly what will my coverage be on January 1?” — Medicare Plan Finder or HICAP.
January to March: one more chance if you are in Medicare Advantage
From January 1 to March 31, people enrolled in a Medicare Advantage plan can make one change: switch to a different Medicare Advantage plan, or go back to Original Medicare (and join a drug plan).
Who this is for
People enrolled in a Medicare Advantage plan on January 1.
What changes it
- People in Original Medicare cannot use this period to join Medicare Advantage.
The question that settles it
“I am in a Medicare Advantage plan. Can I still make one change before March 31, and what would it be?” — HICAP.
Your plan must tell you what changes next year — by September 30
Every Medicare Advantage and drug plan sends an Annual Notice of Change by September 30. It lists next year’s premium, deductibles, copays, covered drugs and their tiers, and network or service-area changes. The three lines most people check first are the monthly premium, the drug deductible, and their own drugs’ tiers.
Who this is for
Everyone enrolled in a Medicare Advantage or Part D plan.
What changes it
- People in Original Medicare without a drug plan do not receive one; Part B costs are announced by Medicare in the fall.
The question that settles it
“Which of my drugs changed tier or gained a restriction for next year?” — your plan, using the notice in hand.
Source: Medicare.gov — Plan Annual Notice of Change (ANOC) ↗
Coverage choices
Medigap fills Original Medicare’s gaps — and has its own six-month window
A Medigap (Medicare Supplement) policy is private insurance that pays some of what Original Medicare does not, such as coinsurance and deductibles. Plans are standardized by letter. Your best guaranteed chance to buy one is the six months starting when you are 65 or older and enrolled in Part B; after that, an insurer can often ask health questions and charge more or refuse.
Who this is for
People choosing Original Medicare.
What changes it
- Medigap cannot be used with a Medicare Advantage plan.
- California adds its own rights; see the California rules.
The question that settles it
“When does my six-month Medigap open enrollment start and end?” — HICAP or the California Department of Insurance.
California
California’s birthday rule: a yearly chance to change Medigap plans
In California, people who already have a Medigap policy get a yearly window beginning on their birthday — at least 60 days — to switch to another Medigap plan with equal or lesser benefits, from any insurer, without health questions.
Who this is for
California residents who already hold a Medigap policy.
What changes it
- It does not let you move to a plan with more benefits without health questions.
- It does not apply to people in Medicare Advantage.
The question that settles it
“Under California’s birthday rule, which plans can I switch to this year and by what date?” — California Department of Insurance or HICAP.
Source: California Department of Insurance — Medicare Supplement Insurance ↗
Under 65 in California? You may have Medigap rights other states do not give
Federal law does not guarantee Medigap to people under 65. California requires Medigap insurers to offer coverage to many people who have Medicare because of a disability, with a six-month open enrollment when Part B starts. Premiums for people under 65 can be higher, and a second six-month window usually opens at 65.
Who this is for
California residents under 65 who have Medicare because of a disability.
What changes it
- People whose Medicare is based only on end-stage renal disease are generally excluded.
The question that settles it
“I am under 65 with Medicare because of disability. Which Medigap plans must be offered to me in California, and when does my window run?” — HICAP.
Source: California Department of Insurance — Medicare Supplement Insurance ↗
California savings programs: income and asset rules apply
California reinstated Medicare Savings Program asset limits in 2026. Income, household size and asset exclusions affect eligibility. Ask the county office to apply current DHCS rules; this page does not determine eligibility.
Who this is for
California residents with Medicare and limited income.
What changes it
- Income limits still apply and change yearly; the county office decides.
The question that settles it
“I was turned down before because of savings. Can I reapply now?” — your county Medi-Cal office or HICAP.
Source: California Department of Health Care Services — Medicare Savings Programs in California ↗
Help with costs
Medicare Savings Programs can pay your Part B premium — and sometimes much more
There are levels. QMB pays Part A and Part B premiums, deductibles, coinsurance and copays, and providers may not bill you for Medicare-covered services. SLMB and QI pay the Part B premium. Which level applies depends on income limits set each year. Qualifying for any level also automatically qualifies you for Extra Help with drug costs.
Who this is for
People with Medicare and limited income.
What changes it
- Income limits change every year; the agency, not this site, decides.
The question that settles it
“Which Medicare Savings Program level might I qualify for, and will you help me apply?” — California HICAP or your county Medi-Cal office.
Extra Help lowers what you pay for prescriptions
Extra Help is a Medicare program that pays most of the Part D premium and deductible and caps what you pay for each prescription at a low amount. You apply through Social Security; people in a Medicare Savings Program or Medi-Cal get it automatically.
Who this is for
People with Medicare drug coverage and limited income and resources.
What changes it
- You still need to be in a Medicare drug plan; Extra Help lowers its cost rather than replacing it.
The question that settles it
“Can I apply for Extra Help, and which drug plans work best with it in my county?” — Social Security (apply) and HICAP (plan help).
A higher Part B bill is based on a tax return from two years ago — and can be appealed
If your income was above a threshold two years ago, Social Security adds an income-related amount (IRMAA) to your Part B and Part D premiums. If your income has since dropped because of a life-changing event — retirement, loss of a spouse, divorce, reduced work — you can ask Social Security to use your current income instead, using form SSA-44.
Who this is for
People whose Part B premium notice shows an income-related amount.
What changes it
- A drop in income without a qualifying life-changing event usually has to wait for the normal two-year cycle.
The question that settles it
“My income dropped because of [event]. Can I file SSA-44 to lower my Part B premium?” — Social Security.
Get help
Free Medicare counseling
California HICAP offers free, confidential Medicare counseling. Ask the local program about language and appointment availability.
California HICAP1-800-MEDICARE
Call 1-800-MEDICARE and ask for an interpreter. TTY: 1-877-486-2048.
Call Medicare · 1-800-633-4227Official information in other languages ↗External resource. Some pages are in English; ask for language assistance if needed.