Tribal nations

Medicare, the Indian Health Service and Tribal Health Care in Arizona

American Indian and Alaska Native people in Arizona can keep using Indian Health Service, tribal and urban Indian clinics after they join Medicare. Enrolling lets those clinics bill Medicare for your care, which brings resources back to the facility, and gives you coverage at other Medicare providers. IHS, tribal and urban Indian drug coverage counts as creditable for Part D, so you won't owe a late penalty for the time you relied on it.

Arizona's tribal nations and Indian health care

Arizona is home to 22 federally recognized tribal nations, according to the Arizona Governor's Office on Tribal Relations. Their lands range from the Navajo Nation and the Hopi Tribe on the Colorado Plateau, to the Apache nations of the White Mountains and San Carlos, to the Tohono O'odham Nation and Pascua Yaqui Tribe in southern Arizona, and the Colorado River tribes along the western border. Many tribal members also live in Phoenix, Tucson, Flagstaff and other cities.

Indian health care in Arizona reaches people through three kinds of providers, often called I/T/U:

Indian Health Service (I)

Federal hospitals and clinics run by IHS. Arizona is served by three IHS Areas: the Phoenix Area (Arizona, Nevada and Utah, including the Phoenix Indian Medical Center), the Navajo Area (the Navajo Nation in Arizona, New Mexico and Utah, with service units such as Chinle and Kayenta), and the Tucson Area (the Tohono O'odham Nation and the Pascua Yaqui Tribe).

Tribal health programs (T)

Hospitals and clinics a tribe or tribal organization runs itself under a self-determination contract or compact, often called "638" programs after Public Law 93-638.

Urban Indian organizations (U)

Nonprofit clinics funded in part by IHS for American Indian and Alaska Native people living in cities. IHS lists Native Health (Phoenix and Mesa) and Native American Connections (Phoenix) in its Phoenix Area, and the Tucson Indian Center in its Tucson Area.

Why enrolling in Medicare helps you and your clinic

If you have always gone to an IHS or tribal clinic, Medicare may not seem necessary. CMS's guide for tribal elders explains why it matters:

Your clinic can bill Medicare. When you have Medicare, IHS, tribal and urban Indian providers can bill Medicare for the care they give you. That money goes back to the facility and helps pay for more services, staff and equipment for the whole community.
Referred care depends on it. Under federal rules (42 CFR 136.61), IHS is the payer of last resort. For Purchased/Referred Care (care from outside providers that IHS arranges), IHS generally won't pay to the extent Medicare, AHCCCS or other coverage would, even if you haven't applied for it. Having Medicare can keep referrals from being delayed or denied.
You have coverage away from your clinic. With Original Medicare you can see any doctor or hospital in the U.S. that accepts Medicare, which helps when you live off the reservation, travel, or need a specialist your clinic can't provide.

You don't give anything up. You can keep using IHS, tribal and urban Indian clinics after you join Medicare. Medicare is an added resource, not a replacement.

Original Medicare or Medicare Advantage?

This is the main choice, and for many people who rely on Indian health care it turns on one question: will your clinic be paid?

Question	Original Medicare	Medicare Advantage
Can I still use my IHS, tribal or urban clinic?	Yes, and the clinic is paid for Medicare-covered services	Yes, but if the clinic is out of the plan's network, it may not be paid
Other providers	Any provider in the U.S. that accepts Medicare	Usually the plan's network; some plans pay out of network at higher cost
Drug coverage	Add a Part D plan, or rely on I/T/U pharmacy coverage	Usually included

CMS advises calling your Indian health care provider before you join a Medicare Advantage plan to ask whether the clinic works with that plan. Plan choices vary by county; on the Navajo Nation, for example, CMS lists 7 Medicare Advantage plans open to everyone in Apache County for 2027 and 8 in Navajo County, compared with 52 in Maricopa County. See Medicare Advantage in Arizona.

Part D: your I/T/U coverage is creditable

A Part D plan can charge a lifetime late enrollment penalty to people who go without creditable drug coverage after their first chance to enroll. Drug coverage from IHS, Tribal Health Programs and Urban Indian Organizations is creditable coverage: the Indian Health Service confirmed this in an October 15, 2026 letter to tribal and urban Indian leaders, citing section 1860D-13(b) of the Social Security Act. That means:

You can rely on your clinic's pharmacy and join a Part D plan later without a late penalty for that time.
A plan may ask you to attest to, or document, your prior coverage when you enroll late or appeal a penalty. Ask your clinic's business office or benefits coordinator for the IHS creditable coverage letter and keep a copy.

Whether to add Part D depends on whether you fill prescriptions outside I/T/U pharmacies. If you do, a Part D plan caps your yearly out-of-pocket drug costs at $2,100 (2026), and Extra Help can lower costs further for people with limited income. See Part D in Arizona.

Help paying Medicare costs

Part A has no premium for most people with 40 quarters of work (yours or a spouse's).
Part B has a monthly premium ($202.90 in 2026). If you delay Part B without other qualifying coverage, the premium can go up 10% for each full year you could have had it. IHS is not employer coverage, so it doesn't protect you from the Part B penalty.
Tribal sponsorship. CMS notes that some tribes pay Medicare premiums for tribal members. Ask your clinic whether yours does.
Medicare Savings Programs through AHCCCS can pay the Part B premium, and sometimes deductibles and coinsurance, for people with limited income. See Medicare Savings Programs in Arizona.

AHCCCS and the American Indian Health Program

American Indian and Alaska Native people enrolled in AHCCCS (Arizona's Medicaid program) can choose the American Indian Health Program (AIHP) or an AHCCCS Complete Care health plan, and can switch between AIHP and a health plan and back at any time, according to AHCCCS. AIHP members can get care from IHS facilities, tribal 638 programs, urban Indian clinics and other AHCCCS-registered providers. AHCCCS also runs a Tribal ALTCS program for long-term care.

Federal Medicaid rules (42 CFR 447.56) also protect American Indians: anyone who has ever received a service from an Indian health care provider, or through a referral from one, is exempt from Medicaid cost sharing, and eligible American Indians are exempt from Medicaid premiums. If you have both Medicare and AHCCCS, see AHCCCS and Medicare for how the two work together.

Enrollment rules: don't mix up Medicare and the Marketplace

You may have heard that American Indians can sign up for coverage any time and change plans every month. That is a Health Insurance Marketplace rule (HealthCare.gov) for members of federally recognized tribes and Alaska Native Claims Settlement Act shareholders. It does not apply to Medicare. For Medicare, the usual windows apply: your Initial Enrollment Period around your 65th birthday, the Annual Enrollment Period (October 15 to December 7), and Special Enrollment Periods, including those for people with AHCCCS or Extra Help. See Medicare enrollment periods.

The Navajo Nation and other tribes that cross state lines

The Navajo Nation spans Arizona, New Mexico and Utah, and the IHS Navajo Area serves all three. Medicare Advantage and Part D plans, though, are sold by where you live: your plan options come from the county and state of your permanent residence, not from your tribal affiliation or the IHS service unit you use. If you live in Arizona and get care in New Mexico or Utah, check whether a plan covers those providers before you join. Original Medicare works in all three states.

Next steps

Talk with the benefits coordinator or business office at your IHS, tribal or urban Indian clinic about enrolling in Medicare, AHCCCS and Medicare Savings Programs.
Ask for the IHS creditable coverage letter for your Part D records.
Before choosing a Medicare Advantage plan, ask your clinic whether it works with that plan.
For help comparing plans, call (602) SENIORS (602-736-4677), TTY 711 to reach a licensed insurance agent with Benefits Life, or see plans in your ZIP code. See also Can I use IHS and Medicare?

Sources

Frequently asked questions

If I have IHS, do I need Medicare?

IHS is not insurance, and federal rules make it the payer of last resort: for referred care it generally won't pay when Medicare or another program could. Enrolling in Medicare lets your IHS, tribal or urban Indian clinic bill Medicare, which adds resources for the clinic, and it covers you at other doctors and hospitals that accept Medicare, including when you travel.

Will I pay a Part D late enrollment penalty if I relied on IHS for prescriptions?

No. The Indian Health Service confirmed in an October 2026 letter that drug coverage through IHS, Tribal Health Programs and Urban Indian Organizations is creditable coverage for Part D, so a Part D plan can't charge you the late enrollment penalty for that time. Ask your clinic for its creditable coverage letter in case the plan asks for proof.

Can I use my IHS or tribal clinic if I join a Medicare Advantage plan?

You can still go to your clinic, but CMS warns that if the clinic is not in the plan's network, it may not be paid for the services it gives you. CMS advises contacting your Indian health care provider before you enroll in a Medicare Advantage plan to check how the plan works with the services you get there.

Is there a special Medicare enrollment period for American Indians?

No. The rule that lets members of federally recognized tribes enroll any time and change plans monthly applies to the Health Insurance Marketplace, not Medicare. For Medicare, the usual enrollment periods apply, along with the special enrollment periods anyone may qualify for, such as those for people with AHCCCS or Extra Help.

Does my tribe pay my Medicare premiums?

Some do. CMS notes that some tribes pay Medicare premiums on behalf of tribal members, which it calls sponsorship. Ask your clinic's benefits coordinator or business office whether your tribe does. AHCCCS Medicare Savings Programs can also pay the Part B premium if your income qualifies.

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