Insurance education
Medicare Supplement (Medigap) Insurance Explained
Original Medicare pays for a large share of your health care costs, but not all of them. You are still responsible for deductibles, coinsurance and copayments. A Medicare Supplement, also called Medigap, is private insurance designed to help pay some of those costs.
How Medigap Works With Original Medicare
Medigap works alongside Original Medicare (Parts A and B). Medicare pays its share of a covered service first. Your Medigap policy then pays its share, depending on the plan you have.
In general, Medigap policies let you see any doctor or hospital in the U.S. that accepts Medicare. Most do not use networks. One exception is Medicare SELECT, a type of Medigap policy that uses a network of hospitals.
Standardized Plans
Medigap plans are standardized and identified by letters, such as Plan G and Plan N. In California, as in most states, a plan with a given letter has the same basic benefits no matter which insurance company sells it. What differs between companies is the premium, how premiums are set and the service you receive.
Plans C and F are not available to people who became eligible for Medicare on or after January 1, 2020. People who were eligible before that date may still be able to buy them.
What Medigap Does Not Cover
- Medigap does not include prescription drug coverage. Most people pair it with a Part D plan.
- Medigap generally does not cover routine dental, vision, hearing aids or long-term care.
- Each policy covers one person. Spouses need their own policies.
- You cannot use a Medigap policy with a Medicare Advantage plan.
When to Apply
Timing matters with Medigap. Your Medigap Open Enrollment Period lasts six months and starts the first month you are both 65 or older and enrolled in Part B. During this window, insurance companies generally cannot refuse to sell you a policy or charge you more because of your health.
Outside that window, companies may be able to ask health questions and decline an application, except in certain protected situations.
California's Medigap Birthday Rule
California gives people who already have a Medigap policy a valuable yearly protection, often called the birthday rule (California Insurance Code Section 10192.11).
- Who qualifies: California residents who already have an active Medigap policy.
- When it happens: a 60-day window that begins on your birthday each year. Your insurance company must notify you of this right between 30 and 60 days before the window begins.
- What you can do: switch to another Medigap policy with equal or lesser benefits — with your current company or a different one.
- No health questions: during this window, the new policy is guaranteed issue. The company cannot deny your application or charge you more because of your health.
This matters because Medigap premiums generally rise as you get older. The birthday rule lets you shop for a lower premium each year without losing access to coverage, as long as the new policy offers equal or lesser benefits. Before switching, compare the benefits side by side, and never cancel your current policy until the new one is approved and in force. We can explain how these rules apply to your situation.
Medigap or Medicare Advantage?
Medigap and Medicare Advantage are two different approaches. Medigap usually means a higher monthly premium and fewer costs when you use care, with broad freedom to choose providers. Medicare Advantage often has lower premiums and uses networks and copays. Compare the two on our Medicare Advantage page.
Talk With Us About Your Situation
Reading about Medicare Supplement insurance is a good start. Your own situation is what really matters. If you would like to talk through your options, call us at 310-440-0281 or toll free at (844) 532-9009, or contact us here. We will listen first, answer your questions and explain the choices available to you. There is no obligation to enroll in anything.