QUICK ANSWER: Medicare Part B covers a screening mammogram once every 12 months for women age 40 and older, at no cost to you — no coinsurance and no Part B deductible — as long as the provider accepts Medicare assignment. Medicare also covers one baseline screening mammogram for women between 35 and 39. There is no upper age limit: screening coverage continues at 65, 75, 85, and beyond. Diagnostic mammograms — ordered because of a symptom, a lump, or to take a closer look at something a screening found — are covered too, but they are not free: you pay 20% of the Medicare-approved amount after the Part B deductible, and Medicare covers them as often as medically necessary, which can be more than once a year.

Mammograms are one of the clearest examples of how Medicare treats preventive care differently from diagnostic care. The screening version is one of Medicare’s most generous benefits — covered every year at no cost to you. But the moment a mammogram is used to investigate a symptom or follow up on a finding, different cost rules apply. Here is how it works for California Medicare beneficiaries in 2026.

Screening vs. diagnostic: why the same machine can produce two different bills

The distinction is purpose, not equipment.

A screening mammogram is routine: you have no symptoms, and the test is looking for problems before any sign of them. Medicare’s preventive benefit applies, and the visit should cost you nothing when the provider accepts assignment.

A diagnostic mammogram is investigative: your doctor orders it because of a symptom (a lump, pain, discharge, skin change) or because a screening mammogram showed something that needs a closer look. The preventive benefit does not apply — standard Part B cost-sharing does.

This is the same preventive-versus-diagnostic line that surprises people with colonoscopies, and it runs through most of the questions in our “Does Medicare cover it?” series. There is one practical difference: a colonoscopy can be reclassified mid-procedure, while with mammograms the callback is usually a separate, second appointment. If you are called back after a screening, that follow-up imaging is diagnostic — expect cost-sharing, and know that the callback itself is common and most callbacks do not find cancer.

How often does Medicare pay for a mammogram?

What about 3D mammograms (tomosynthesis)?

Medicare covers digital breast tomosynthesis — the 3D mammogram many California imaging centers now use by default. When it is performed as part of your annual screening, it falls under the same no-cost screening benefit. If your imaging center offers 3D as an upgrade, confirm before the appointment that it will be billed to Medicare as a screening, so you are not billed separately for the 3D portion.

What Medicare does not cover here

Medicare Advantage, Medigap, and what changes

If you have a Medicare Advantage (Part C) plan, it must cover screening mammograms at least as well as Original Medicare — so your annual screening should also be $0 — but the plan can require you to use in-network imaging facilities, and diagnostic imaging copays are set by the plan. In Southern California’s HMO-heavy market, that usually means getting imaging done through your medical group’s contracted centers. Check your plan’s Evidence of Coverage for the plan year you are in. Many Advantage plans also bundle extras Original Medicare leaves out, such as dental, vision, and hearing benefits, but the mammogram benefit itself is the same federal floor everywhere.

If you have Original Medicare with a Medigap (Medicare Supplement) policy, the screening is $0 either way, and most Medigap plans pick up some or all of the 20% coinsurance on diagnostic mammograms.

Current Part B deductible and other dollar amounts are published at Medicare.gov — they can change each January 1. For how deductibles and coinsurance fit together across Parts A, B, and D, see our overview of what Medicare costs.

Frequently asked questions

Is a mammogram free with Medicare?
A screening mammogram is, once every 12 months for women 40 and older, with no coinsurance and no Part B deductible when the provider accepts Medicare assignment. A diagnostic mammogram is covered but has standard Part B cost-sharing.
How often will Medicare pay for a mammogram after 65?
Once every 12 months for screening, with no upper age limit. Diagnostic mammograms are covered whenever medically necessary, even more than once a year.
Why did I get a bill after my “free” mammogram?
The most common reasons: the imaging was billed as diagnostic rather than screening because of a symptom or a callback, it was less than 12 months since your last screening, or the facility did not accept assignment. If the bill looks wrong, ask the imaging center how it was coded before paying.
Does Medicare cover 3D mammograms?
Yes. Digital breast tomosynthesis performed as part of an annual screening falls under the screening benefit. Confirm the facility bills it as a screening.
Does Medicare cover mammograms for men?
The routine screening benefit is for women. For men, breast imaging can be covered as a diagnostic test under Part B when a doctor orders it for a medical reason, such as a lump, with standard cost-sharing.

Where to get help in Southern California

Free, unbiased Medicare counseling is available through HICAP — California’s State Health Insurance Assistance Program (SHIP) at 1-800-434-0222. You can also compare every plan in your ZIP code at Medicare.gov or by calling 1-800-MEDICARE.

If you would like one-on-one help understanding what your plan covers — or comparing plans during the Annual Enrollment Period (October 15 – December 7) or the Medicare Advantage Open Enrollment Period (January 1 – March 31) — an independent licensed broker can walk through it with you at no cost, because brokers are paid by the insurance carriers. A broker may not offer every plan available in your area; contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Assistance Program (SHIP) for information on all of your options. New to Medicare entirely? The turning 65 guide covers enrollment step by step.

Sources & official references

This is a non-government resource and is not affiliated with or endorsed by Medicare.gov or the federal Medicare program. We do not offer every plan available in your area. Please contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Assistance Program (SHIP) — in California, the Health Insurance Counseling and Advocacy Program (HICAP) — to get information on all of your options. Matt Medicares Insurance is an independent insurance brokerage and is not affiliated with or endorsed by Medicare, the Centers for Medicare & Medicaid Services, or any government agency. Educational information only, not individualized advice. Last reviewed: September 2026. Medicare figures reflect 2026 and can change annually — confirm current amounts at Medicare.gov.