People in California have access to 465 Medicare Advantage plans, 18 prescription drug plans, and 11 Medigap plans. Your exact options depend on where you live.
Medicare is a health insurance program designed for individuals ages 65 and older, as well as younger individuals with specific health conditions and disabilities.
It consists of four parts:
- Part A (hospital insurance) and Part B (medical insurance) together form Original Medicare
- Part C, referred to as Medicare Advantage, provides an alternative to Original Medicare
- Part D offers coverage for prescription drugs
If you have Original Medicare, you can also sign up for a supplemental insurance plan (Medigap) to help cover out-of-pocket costs.
According to the Centers for Medicare & Medicaid Services (CMS), 6,880,905 people in California are enrolled in Medicare.
The CMS reported the following trends for the 2025 plan year:
- The average Medicare Advantage monthly premium decreased by $3.77 — from $16.25 in 2024 to $12.48 in 2025.
- The number of available Medicare Advantage plans increased by 44 — from 421 in 2024 to 465 in 2025.
- All Medicare beneficiaries have the option to enroll in a Medicare Advantage plan, including plans with $0 premiums.
- All Original Medicare enrollees have the option to buy a stand-alone prescription drug plan.
- There are 18 stand-alone prescription drug plans available, and the lowest monthly premium is $1.80.
- About 67% of people with a stand-alone prescription drug plan have the option to enroll in a plan with a lower premium than they paid in 2024.
- About 32% of people with a stand-alone prescription drug plan receive Extra Help.
Each part of Medicare covers specific services, so it’s important to understand the details of each type.
Original Medicare
Original Medicare is a federal program that includes Part A and Part B. It’s available to anyone eligible for Medicare.
Most people qualify for premium-free Part A. In 2025, the standard monthly premium for Part B is estimated to be $185, but your premium may be higher based on your income.
Medicare Advantage
Medicare Advantage plans are offered by private insurers that partner with Medicare to bundle Part A and Part B coverage with additional health and wellness benefits.
Many of these plans also include prescription drug coverage, as well as certain vision, dental, and hearing services.
Some of the companies that offer Medicare Advantage plans in California include:
- Aetna Medicare
- Alignment Health Plan
- Align Senior Care
- Anthem Blue Cross
- Anthem Blue Cross Life and Health Insurance Company
- Anthem Blue Cross Partnership Plan
- CCHP (Chinese Community Health Plan)
- Central Health Medicare Plan
- Humana
- Imperial Health Plan of California, Inc.
- Kaiser Permanente
- SCAN Health Plan
- UnitedHealthcare
- Wellcare by Health Net
Service areas can vary by plan. Each plan sets its own cost and coverage amounts.
Stand-alone prescription drug plans
Private insurance companies contract with Medicare to offer prescription drug coverage. You must be enrolled in Part A or Part B to be eligible.
People in California can choose from 18 different prescription drug plans offered by some of the following companies:
- Aetna Medicare
- Anthem / Anthem or Blue KC in Missouri
- Blue Shield of California
- Cigna Healthcare
- Humana
- UnitedHealthcare
- Wellcare
Service areas can vary by plan. Each plan sets its own cost and coverage amounts.
Medigap
Private insurance companies also partner with Medicare to offer supplemental coverage for Original Medicare beneficiaries.
Medigap isn’t health insurance; it’s designed to help cover out-of-pocket expenses, such as deductibles, copayments, and coinsurance.
People in California can choose from 11 different Medigap plans:
Some of the companies that offer Medigap plans in California include:
- Ace Property and Casualty Insurance Company
- AFLAC
- Allstate Health Solutions
- American Retirement Life Insurance Company (CIGNA)
- Anthem BlueCross
- Blue Shield of California Life & Health Insurance Company
- Continental Life Insurance Company of Brentwood, Tennessee (Aetna)
- Everence Association Inc.
- Globe Life and Accident Insurance Company
- Health Net Life Insurance Company
- Humana Achieve (Humana Benefit Plan of Illinois, Inc.)
- Humana (Humana Insurance Company)
- Manhattan Life Assurance Company
- Mutual of Omaha (United World Life Insurance Company)
- Physicians Select Insurance Company
- State Farm Mutual Automobile Insurance Company
- Transamerica Life Insurance Company
- United American Insurance Company
- UnitedHealthcare/AARP
- USAA Life Insurance Company
- Washington National Insurance Company
Service areas can vary by plan. Each plan sets its own cost and coverage amounts.
You’re eligible for Medicare if you:
- are age 65 or over
- are a U.S. citizen or legal resident of at least 5 years
If you’re under age 65, you may be eligible for Medicare if you:
- received Social Security Disability Insurance (SSDI) or Railroad Retirement Board (RRB) benefits for at least 24 months
- have end stage renal disease (ESRD) or a kidney transplant
- have amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease
When can you enroll in Medicare in California?
You can enroll in Medicare or change your coverage during specific periods:
- Initial Enrollment Period (IEP): This lasts for seven months — three months before your 65th birthday, your birth month, and three months after.
- Open Enrollment Period (OEP): From October 15 to December 7, you can enroll, switch plans, or drop coverage.
- Medicare Advantage OEP: If you’re already enrolled in a Medicare Advantage plan, you can make changes from January 1 to March 31.
- Medigap OEP: You have six months after turning 65 to enroll in Medigap.
Certain life events can trigger a special enrollment period, allowing you to sign up for Medicare outside of standard enrollment.
Tips for enrolling in Medicare in California
To help you narrow down your options, consider the following:
- Provider network: To maximize your benefits with a Medicare Advantage plan, you may need to use in-network providers. Before enrolling, verify that your healthcare team is included in the network.
- Prescription drugs: Create a complete list of your medications and compare it with the coverage offered by stand-alone prescription drug plans and Medicare Advantage plans in your area. Ensure your medications are covered and reasonably priced.
- Travel coverage: Some Medicare Advantage plans provide coverage outside the plan’s service area. If you travel frequently, it may be beneficial to choose a plan that offers this coverage.
- Plan performance: The CMS publishes annual ratings for Medicare plans, ranging from one to five stars, with five being the best rating.
Medicare has a helpline with staff available 24 hours a day, 7 days a week (excluding some federal holidays) to answer your questions. You can call Medicare at 1-800-633-4227 (TTY: 1-877-486-2048).
For personalized health insurance counseling, contact HICAP, California’sState Health Insurance Assistance Program (SHIP), at 1-800-434-0222.
More than 6.8 million California residents are enrolled in Medicare.
Dozens of private insurance companies offer Medicare Advantage, Medigap, and stand-alone prescription drug coverage throughout the state.
Overall, monthly premium costs have decreased for Medicare Advantage plans in California.