Original Medicare is the foundation of your Medicare coverage. It has two parts: Part A (health insurance) and Part B (medical insurance). Part B has a monthly premium. In general, prescriptions are not covered by Original Medicare.
You must enroll in Medicare to begin coverage. If you are 65 or older, you are eligible to enroll in Original Medicare. Some people younger than 65 with certain disabilities are also eligible.
The Initial Enrollment Period (IEP) lasts seven months. It begins three months before the month you turn 65. It ends three months after the month you turn 65. This applies whether you retire at age 65 or you’re enrolled in Covered California.
During the IEP, you can make more choices about your Medicare coverage.
- Bundle your plans with a Medicare Advantage (Part C) plan
- Pick a Prescription Drug Coverage (Part D) plan
- Add a Medicare Supplement plan
Covered California
If you get a subsidy from California you may no longer qualify for it when you become eligible for Medicare.1 And if you continue to get a subsidy after that time, you may have to pay back some or all of the money.
It’s important to discuss your options. Call a Blue Shield Medicare Advisor at (855) 203-3874* to learn more about your options.
How to enroll in Original Medicare
Call Social Security at (800) 772-1213, 8 a.m. to 7 p.m., Monday through Friday. TTY users should call 1-(800) 325-0778. You can also visit your local Social Security office.
If you have health insurance through your employer or your spouse’s employer, check your options before signing up for Part B. Depending on your coverage, you may not need Part B and can avoid paying the monthly premium. Ask your benefits administrator or HR representative for help in choosing the right option for you. Or call Blue Shield of California toll free at (855) 203-3874*. We’re here to help.
Get more information
Get a free copy Medicare guide to understand your coverage options.
Learn how to enroll in Medicare plans beyond the initial enrollment period (IEP).
Get answers to some of our most frequently asked questions about Medicare.
1 There is one exception: if you have to pay a premium for Medicare Part A coverage and you have not enrolled in it, you may be able to continue Covered California coverage instead and keep your financial assistance. Call Medicare for more information at 1-800-MEDICARE (1-800-633-4227. TTY users can call 1-877-486-2048), 24 hours a day, seven days a week, except holidays.
Blue Shield of California is an HMO, HMO D-SNP, and a PDP plan with a Medicare contract and a contract with the California State Medicaid Program. Enrollment in Blue Shield of California depends on contract renewal.
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Page last updated: 10/1/2026