Nearly 6.6 million people in California are signed up for Medicare, making it the largest U.S. state for Medicare beneficiaries.

Medicare is the federal health insurance program for people of ages 65 and older. Medicare Advantage is a bundled alternative to Medicare sold by private insurance companies. It offers all the same benefits and usually some extras, such as cost help with dental and vision coverage.

Medicare Advantage plans offer more benefits than Original Medicare, and they're often cheaper than paying for Medicare and a Medicare Supplement plan. However, they offer less flexibility since you’ll need to get care from within the plan’s network of providers. Weigh your options to determine what plan best suits your needs.

» MORE: Medicare vs. Medicare Advantage: Which should I choose?

What to know about Medicare in California
Nearly 1 in 6 people in California are age 65 and older, and there are a wide variety of Medicare Advantage plans in the state.

The average monthly premium in 2023 for a Medicare Advantage plan in California is $16.42. (This is down from $18.14 in 2022.)

There are 492 Medicare Advantage plans available in California in 2023. (This is up from 458 plans in 2022.)

Over 99 percent of Medicare-eligible people in California have access to a $0-premium Medicare Advantage plan.

Medicare Advantage companies in California
Aetna Medicare.

Alignment Health Plan.

Anthem Blue Cross.

Aspire Health.

Astiva Health.

Blue Shield of California.

Brand New Day.

CCA Health California.

Central Health Medicare Plan.

Chinese Community Health Plan.

Clever Care Health Plan.

Essence Healthcare.

Humana.

Imperial Health Plan of California.

Integrated HealthPlan.

Kaiser Permanente.

Molina Healthcare of California.

Providence Medicare Advantage Plans.

SCAN Health Plan.

Sharp Health Plan.

UnitedHealthcare.

Wellcare.

Wellcare by Health Net.

Western Health Advantage.

Top-rated Medicare Advantage plans in California
Each year, the Centers for Medicare & Medicaid Services, or CMS, awards every Medicare Advantage plan a star rating on a scale of 1 to 5, with 5 being a top-rated plan. Below are companies with plans that received top marks in California for the 2023 plan year. (Check out more information about Medicare star ratings.)

5-star plans
The companies below offers plans in California that are rated 5 stars out of 5 by CMS:

Kaiser Permanente.

Sharp Health Plan.

4.5-star plans
The company below offers plans in California that are rated 4.5 stars out of 5 by CMS:

SCAN Health Plan.

This list doesn’t include special needs plans, which restrict membership to people with certain diseases or characteristics, such as having a chronic illness or living in a nursing home.

» MORE: Best Medicare Advantage plans
Find the right Medicare Advantage plan
It’s important to do your research before selecting a Medicare Advantage plan for yourself. Here are some questions to consider asking:

What are the plan’s costs? Do you understand what the plan’s premium, deductibles, copays and/or coinsurance will be? Can you afford them?

Is your doctor in-network? If you have a preferred medical provider or providers, make sure they participate in the plan’s network.

Are your prescriptions covered? If you’re on medication, it’s crucial to understand how the plan covers it. What tier are your prescription drugs on, and are there any coverage rules that apply to them?

Is there dental coverage? Does the plan offer routine coverage for vision, dental and hearing needs?

Are there extras? Does the plan offer any extra benefits, such as fitness memberships, transportation benefits or meal delivery?

Medicare Advantage companies
Get more information below about some of the major Medicare Advantage companies. These insurance companies offer plans in most states. The plans you can choose from will depend on your ZIP code and county.

AARP Medicare Advantage plans.

Aetna Medicare Advantage plans.

Anthem Medicare Advantage plans.

Blue Cross Blue Shield Medicare Advantage plans.

Cigna Medicare Advantage plans.

Humana Medicare Advantage plans.

Kaiser Permanente Medicare Advantage plans.

UnitedHealthcare Medicare Advantage plans.

Wellcare Medicare Advantage plans.

If you have additional questions about Medicare, visit Medicare.gov or call 800-MEDICARE (800-633-4227, TTY 877-486-2048).
Looking for additional insurance in California? Check out these resources:

California car insurance.

California homeowners insurance.

California renters insurance.

About the author: Kate Ashford is a certified senior advisor (CSA)® and personal finance writer at NerdWallet specializing in Medicare and retirement topics. Read more