Who pays first
Medicare.gov says that if you have Medicare and get care from IHS or an IHS provider, Medicare generally pays first, before the IHS delivery system, which includes IHS, tribal and urban Indian facilities. Federal rules make IHS the payer of last resort for Purchased/Referred Care (42 CFR 136.61). If you also have job-based group coverage from a non-tribal employer with 20 or more employees, that plan pays first and Medicare second.
Arizona is served by three IHS Areas: Phoenix, Navajo and Tucson. Some tribes run their own health programs under agreements with IHS, and urban Indian organizations serve people living in cities.
Why enrolling in Medicare helps
- It supports your clinic. When Medicare pays an IHS or tribal facility for your care, that money stays in the local health system.
- It covers care IHS may not. Purchased/Referred Care funds are limited and prioritized. With Medicare, you can see specialists and use hospitals off the reservation, anywhere in the U.S. that accepts Medicare.
- It travels with you. Medicare works in Phoenix, Tucson, Flagstaff or out of state, where your IHS facility may be far away.
Part A and Part B
Most people pay no premium for Part A, so there's little reason to delay it. Part B has a monthly premium ($202.90 standard in 2026). IHS coverage doesn't count as job-based group health coverage, so it doesn't let you put off Part B without a late penalty. If the premium is hard to afford, AHCCCS's Medicare Savings Programs may pay it. See does AHCCCS pay Medicare premiums.
Part D and creditable coverage
Drug coverage through IHS, tribal and urban Indian (I/T/U) programs is creditable for Part D. Federal rules list it among the kinds of coverage that can be creditable (42 CFR 423.56(b)(9)), and an October 15, 2026 IHS letter to tribal leaders confirms a Part D plan can't charge you a late penalty for time you had I/T/U drug coverage. You may be asked for proof when you join a Part D plan after your first chance, so ask your facility for the IHS creditable coverage letter.
Whether you join a Part D plan is your choice. Some people get everything they need at an IHS pharmacy; others join a plan to fill prescriptions at outside pharmacies. If you have AHCCCS or limited income, Extra Help can lower Part D costs.
AHCCCS and the American Indian Health Program
If you also qualify for AHCCCS, you can choose the American Indian Health Program (AIHP), AHCCCS's fee-for-service program for American Indian and Alaska Native members, or an AHCCCS Complete Care plan, and AHCCCS says you can switch at any time. Members who need long-term care and live on a reservation can get Tribal ALTCS. See Tribal Nations and IHS.
Get help
Your facility's benefits coordinator or business office can help you sign up for Medicare and AHCCCS. To compare Medicare plans from the companies they work with, you can talk with a licensed insurance agent with Benefits Life at (602) SENIORS (602-736-4677), TTY 711.
Related questions
Does AHCCCS pay Medicare premiums?
QMB Only, SLMB and QI-1 in Arizona.
Do I need Part B if I'm still working?
The 20-employee rule and the Part B penalty.
When can I change my Medicare plan?
Yearly windows and Special Enrollment Periods.
Sources
- Medicare.gov — How Medicare works with other insurance (Indian Health Services)
- Indian Health Service — Dear Tribal Leader and Urban Indian Organization Leader letter on Part D creditable coverage, October 15, 2026
- Indian Health Service — Medicare Part D creditable coverage letters
- 42 CFR 423.56 — Procedures to determine and document creditable status of prescription drug coverage
- 42 CFR 136.61 — Payor of last resort
- Indian Health Service — Phoenix Area
- Indian Health Service — Navajo Area
- Indian Health Service — Tucson Area
- AHCCCS — American Indian Health Program
- Medicare.gov — Avoid late enrollment penalties
Frequently asked questions
Do I lose IHS if I sign up for Medicare?
No. You can keep using IHS, tribal and urban Indian clinics. Medicare simply pays the facility for covered services, and IHS remains available for care Medicare doesn't cover.
Will I pay a Part D penalty if I only used IHS for prescriptions?
No. In an October 15, 2026 letter to tribal leaders, IHS confirmed that drug coverage through IHS, tribal and urban Indian programs is creditable coverage, so a Part D plan can't charge a late enrollment penalty for that time. Ask your facility for an IHS creditable coverage letter to keep as proof.
Do I need Part B if I get care at IHS?
IHS isn't job-based group health coverage, so it doesn't let you delay Part B without a penalty. If you don't sign up when first eligible and later want Part B, you may pay a late penalty of 10% for each full 12 months you went without it, for as long as you have Part B.
Who pays first if I have Medicare, AHCCCS and IHS?
Medicare generally pays first, then AHCCCS, and IHS pays last. American Indian and Alaska Native AHCCCS members can choose the American Indian Health Program (AIHP) or an AHCCCS Complete Care health plan.
