Medicare is a federal healthcare program that is used primarily by people age 65 and older. People of any age with disabilities and those with end stage renal disease (ESRD) or amyotrophic lateral sclerosis (ALS) are also able to receive Medicare.

If you live in California and meet the requirements for Medicare, you are eligible for original Medicare (parts A and B) and Medicare Part D, no matter where in the state you live. The availability of Medicare Part C (Medicare Advantage) is different in some areas of California than it is in most other states.

Medicare Part C eligibility in California is based on the county and ZIP code of your primary residence.

Medicare Part A is also known as hospital insurance. Part A covers hospital inpatient care, hospice care, some home health services, and limited stays and services in a skilled nursing facility (SNF).

If you or your spouse worked and paid Medicare taxes for at least 10 years, you will most likely be eligible for premium-free Part A at no monthly cost. Even if you are not eligible for premium-free Part A, you may be able to purchase Part A (premium Part A).

Medicare Part B covers medically necessary services, such as doctor’s appointments and ambulance services. It also covers preventive care, such as many vaccines. Along with Part A, Medicare Part B makes up original Medicare. You will have to pay a monthly premium for Medicare Part B.

Medicare Part C is purchased through private insurers that are approved by Medicare. By law, a Medicare Part C plan must cover at least as much as original Medicare parts A and B, do. Most Part C plans cover more services than original Medicare provides for, but often require that you use a specified network of doctors. Some Medicare Part C plans include prescription drug coverage, but others do not.

Medicare Part C is not available everywhere in California. Some counties have access to many plans. Other counties have access to only a few. Approximately 115 counties in California, such as Calaveras County, do not have access to any Medicare Advantage plans.

Enter your ZIP code here to see Medicare plans available in your area.

Many companies do offer Advantage policies in parts of California. They include:

  • Aetna Medicare
  • Alignment Health Plan
  • Anthem Blue Cross
  • Blue Cross of California
  • Brand New Day
  • Central Health Medicare Plan
  • Clever Care Health Plan
  • Golden State
  • Health Net Community Solutions, Inc.
  • Health Net of California
  • Humana
  • Imperial Health Plan of California, Inc.
  • Kaiser Permanente
  • Scan Health Plan
  • UnitedHealthcare
  • WellCare

Many of the plans offered are Health Maintenance Organization (HMO) plans that start at a $0 monthly premium. The maximum out-of-pocket costs you are required to pay annually can vary significantly for these plans. HMO plans typically also require that you pay a copay at each doctor’s visit.

Other types of Medicare Advantage plans include Preferred Provider Organization (PPO) plans. Some of these may have higher monthly premiums than HMOs in addition to out-of-pocket costs and copays. It is important to review the plans you are considering, as they vary not only in cost but also in the services and coverage provided.

Medicare Part D is the part of Medicare that covers prescription medications. It is meant to be used with original Medicare (parts A and B). If you have an Advantage plan that includes medications, you will not need to purchase a Part D plan as well.

If you don’t have prescription drug coverage through another source, such as the health insurance you get at work, it is important to enroll in Medicare Part D when you are first eligible for Medicare. If you don’t, you may have to pay higher rates in the form of a monthly penalty for the entire duration of your Part D coverage.

Medicare Part D is provided by private insurance companies. There are Part D plans available throughout the entire state of California. These plans vary in terms of the medications they cover, as well as their cost.

Help enrolling in Medicare in California

With so many options, enrolling in Medicare can be confusing. These organizations can provide information you need to choose and enroll in the best Medicare plan for you if you live in California.

Medicare supplement insurance or Medigap is designed to help you pay for the things not covered by original Medicare. These costs include copays, coinsurance, and deductibles. In California, you are able to purchase one of 10 types of standardized plans that are available throughout most of the country.

These standardized plans are designated by alphabet letters: A, B, C, D, F, G, K, L, M, and N. Each plan varies in terms of its deductibles, cost, and coverage. In California, there are many insurers that cover some or all of these plans. Their costs within plans tend to be the same or very similar.

Some companies that offer Medigap in California include:

  • Aetna
  • Anthem Blue Cross – California
  • Blue Shield of California
  • Cigna
  • Combined Insurance Company of America
  • Everence Association Inc.
  • Garden State
  • Globe Life and Accident Insurance Company
  • Health Net
  • Humana
  • Mutual of Omaha
  • National Guardian
  • National Health Insurance Company
  • Oxford
  • Sentinel Security
  • State Farm
  • Thrivent Financial for Luterans
  • USAA
  • United American
  • UnitedHealthcare

Some plans also require that you pay a percentage of the costs for services covered under Part B, plus a Part A deductible.

There is a 6-month open enrollment period when you can get Medigap. This period typically starts on your 65th birthday and coincides with your enrollment in Medicare Part B.

In most of the country, this is the only period of time when you can enroll in a Medigap plan and be assured of getting one, no matter what type of health issues you have.

However, in California, you are allowed to switch to a different Medigap plan with guaranteed issue during the 30 days following your birthday each year, provided the new plan gives you equal or lesser coverage than your current Medigap plan.

The deadlines for Medicare enrollment in California are the same as they are in the rest of the country, with the exception of Medigap, which has additional enrollment periods.

Type of enrollmentDatesRequirements
initial enrollment3 months before and after your 65th birthdayThis is the first time most people are eligible to enroll in original Medicare (parts A and B).
general enrollmentJan. 1–Mar. 31If you miss initial enrollment, you can sign up for Medicare now, but your rates may be higher.
special enrollmentat the time of change in your Medicare status and for 8 months after You can enroll now if you have personal changes in your current health plan, such as losing your health insurance at work, losing coverage through your spouse, or if your Medicare health plan is no longer available in your ZIP code area.
open enrollmentOct. 15–Dec. 7You can change your current plan to a different one and add or drop services.
Medicare supplement (Medigap) enrollmentstarts on your 65th birthday and lasts for 6 monthsIn California, you can change your Medigap plan during the month following your birthday each year.
Medicare Part D enrollmentApr. 1–Jun. 30 (or Oct. 15–Dec. 7 for changes)You can get Medicare Part D during your first initial enrollment period or during general enrollment. It can also be added to your coverage from Apr. 1–Jun. 30 your first year. Changes to Part D can be made from Oct. 15–Dec. 7 annually after your first year of coverage.

Medicare is a federal insurance program that is available in California for those who are eligible. Medicare Advantage (Medicare Part C) is not available throughout every zip code in the state. However, original Medicare (parts A and B), as well as Medicare Part D and Medigap are available in every county and ZIP code.

This article was updated on October 6, 2020 to reflect 2021 Medicare information.


The information on this website may assist you in making personal decisions about insurance, but it is not intended to provide advice regarding the purchase or use of any insurance or insurance products. Healthline Media does not transact the business of insurance in any manner and is not licensed as an insurance company or producer in any U.S. jurisdiction. Healthline Media does not recommend or endorse any third parties that may transact the business of insurance.