Your 7-month Initial Enrollment Period
Most people in Arizona become eligible for Medicare the month they turn 65. Your first chance to sign up is your Initial Enrollment Period: 7 months that start 3 months before your birthday month and end 3 months after it. During this window you can sign up for Part A and Part B, and once you have both you can join a Medicare Advantage plan or a Part D drug plan.
Since January 2023, coverage starts sooner if you sign up late in the window. If you sign up during your birthday month or in the 3 months after, coverage starts the first day of the next month. Coverage always starts on the first of a month. If your birthday is on the 1st, everything moves one month earlier: Medicare treats you as eligible the month before.
Timeline: month by month
Example: you turn 65 on July 15. Your Initial Enrollment Period runs from April 1 to October 31.
| When | Example | What to do | When Part B starts if you sign up then |
|---|---|---|---|
| 3 months before your birthday month | April | Window opens. Sign up with Social Security if you aren't enrolled automatically. Decide about Part B if you are still working. | July 1 (your birthday month) |
| 2 months before | May | Compare Medigap, Medicare Advantage and Part D options. Ask your employer or retiree plan how it works with Medicare. | July 1 |
| 1 month before | June | Last month to sign up for a first-of-birthday-month start. Choose a Part D or Medicare Advantage plan once you have your Medicare number. | July 1 |
| Birthday month | July | Coverage starts if you signed up earlier. Your Medigap open enrollment begins if you have Part B. | August 1 |
| 1 month after | August | You can still sign up without a penalty. | September 1 |
| 2 months after | September | You can still sign up without a penalty. | October 1 |
| 3 months after | October | Last month of the window. After this, you may have to wait for the General Enrollment Period and pay a penalty. | November 1 |
The table is for Part B (and Part A if you have to buy it). Part A without a premium, which most people get after about 10 years of work, starts the month you turn 65 even if you sign up later in the window. More detail is on our enrollment periods page and in When does Medicare start?
If you already get Social Security
If you have been getting Social Security or Railroad Retirement Board benefits for at least 4 months before you turn 65, you are enrolled in Part A and Part B automatically. Your red, white and blue Medicare card arrives in the mail about 3 months before your birthday month. You don't need to do anything to keep both parts. If you have job-based coverage from current work and want to delay Part B, follow the instructions that come with the card before your coverage starts.
Full retirement age is 67 for anyone born in 1960 or later, so many Arizonans turn 65 before they claim Social Security. If that's you, nothing happens automatically: you need to sign up.
How to sign up in Arizona
Social Security handles Medicare enrollment. You have three ways to apply:
- Online at ssa.gov. This is usually the quickest way if you only want Medicare and aren't claiming retirement benefits yet.
- By phone at 1-800-772-1213 (TTY 1-800-325-0778).
- In person at a Social Security office. Use Social Security's office locator with your ZIP code to find the one that serves you, its hours, and whether you need an appointment.
For step-by-step answers, see How do I sign up for Medicare in Arizona?
Still working at 65?
If you or your spouse have health coverage from current work at an employer with 20 or more employees, that plan pays first and you can usually delay Part B without a penalty. When the job or the coverage ends, you get 8 months to sign up. COBRA, retiree coverage and VA health care don't count as coverage from current work. If you delay Part B without that kind of coverage, your Part B premium can go up 10% for each full 12 months you went without it, for as long as you have Part B. Read working past 65 before you decide.
Medigap: Arizona's one guaranteed window
If you plan to keep Original Medicare, your Medigap open enrollment period is the most important deadline after Part B itself. It lasts 6 months and starts the first day of the month you are 65 or older and enrolled in Part B. During it, a company must sell you any Medigap policy it offers in Arizona without health questions, for the same price people in good health pay.
No second chance under state law. Arizona has no birthday rule or yearly right to switch Medigap policies (A.R.S. § 20-1133). After your open enrollment period, an insurer can ask about your health and may turn you down, unless you have a federal guaranteed-issue right. If you delay Part B because you are still working, the window starts later, when your Part B starts.
See Medigap in Arizona and Medicare Advantage vs. Medigap in Arizona.
Part D and the late penalty
Original Medicare doesn't cover most prescriptions you fill at a pharmacy. You can get drug coverage from a stand-alone Part D plan or from a Medicare Advantage plan that includes it. If you go 63 days or more in a row without Part D or other creditable drug coverage after your Initial Enrollment Period, a late penalty is added to your premium for as long as you have Part D: 1% of the national base beneficiary premium ($38.99 in 2026) for each full month without coverage. In 2026 every Part D plan caps your yearly out-of-pocket drug costs at $2,100, and covered insulin costs no more than $35 a month. See Part D in Arizona and the penalty calculator.
Check for help paying costs
Before you choose coverage, check whether you qualify for help. Two programs matter most in Arizona:
AHCCCS Medicare Savings Programs
QMB, SLMB and QI-1 can pay your Part B premium, and QMB also pays Medicare deductibles and coinsurance. In 2026 QMB covers incomes up to about $1,350 a month for one person, and Arizona has no resource test, so savings don't count. Apply through Health-e-Arizona Plus. See Medicare Savings Programs.
Extra Help (Part D)
Lowers Part D premiums and copays. In 2026 the income limit is $23,940 a year for one person. If you qualify for a Medicare Savings Program, you get Extra Help automatically. Otherwise apply with Social Security.
Try the savings programs calculator. If you already have AHCCCS, read AHCCCS and Medicare: Medicare becomes your main coverage at 65 and AHCCCS fills in.
ASRS and other Arizona retiree coverage
Many Arizonans turning 65 are retiring from public employers: state agencies, school districts, community colleges, universities, cities and counties. The Arizona State Retirement System (ASRS) offers health plans for retirees, and it has its own Medicare rules:
- ASRS says you must enroll in and keep both Part A and Part B to join its plans for Medicare-eligible retirees.
- If you are in an ASRS plan for retirees under 65 when you become eligible for Medicare, you must move to one of its Medicare plans to keep ASRS coverage.
- ASRS suggests contacting Medicare about 3 months before your 65th birthday.
If your retiree coverage comes from another employer, a union or another public retirement system, ask the plan administrator how it works with Medicare before you join any individual plan. Joining a separate Medicare Advantage or Part D plan can end some retiree coverage, and you may not be able to get it back. The working past 65 page covers the ASRS premium benefit.
Veterans, TRICARE and IHS
- Military retirees: TRICARE For Life starts only when you have both Part A and Part B, and you must keep paying the Part B premium.
- VA health care: it doesn't let you delay Part B without a penalty. Many veterans keep Part B for care outside the VA. See veterans and military.
- American Indian and Alaska Native people: you can keep using Indian Health Service, tribal and urban Indian clinics after you join Medicare, and enrolling lets those clinics bill Medicare. Their drug coverage counts as creditable for Part D. See tribal nations and IHS.
Your turning-65 checklist
- 4 to 6 months before your birthday month: check whether you will be enrolled automatically, and gather your employer, retiree, VA or TRICARE plan information.
- 3 months before: sign up for Part A and Part B at ssa.gov, by phone or at your local Social Security office, or follow your card's instructions if you are delaying Part B.
- 3 months before: if you're retiring from a public employer, contact ASRS or your plan administrator.
- 2 months before: check whether you qualify for an AHCCCS Medicare Savings Program or Extra Help.
- 2 months before: decide between Original Medicare with Medigap and Part D, or a Medicare Advantage plan. Check that your doctors, hospitals and pharmacies are covered.
- 1 month before: join a Part D or Medicare Advantage plan once you have your Medicare number, so coverage starts with Medicare.
- Birthday month to 6 months after Part B starts: buy a Medigap policy during your open enrollment period if you're keeping Original Medicare.
- Keep records: your Medicare card, enrollment confirmations, and any creditable drug coverage letters.
- Every fall: review your coverage during the Annual Enrollment Period, October 15 to December 7.
To see what's sold in your county, see plans in your ZIP code, or call (602) SENIORS (602-736-4677), TTY 711 to reach a licensed insurance agent with Benefits Life, at no cost to you, about plans from the companies they work with.
Sources
- Medicare.gov — When does Medicare coverage start?
- Social Security — Sign up for Medicare
- Social Security — Office locator
- Medicare.gov — When can I sign up for Medicare?
- Medicare.gov — When can I buy Medigap?
- Arizona Legislature — A.R.S. § 20-1133, Medicare supplement insurance
- NAIC — State Medigap rules: "Birthday Rule" and coverage for under 65, as of May 11, 2026
- Medicare.gov — Part D late enrollment penalty
- AHCCCS — Qualified Medicare Beneficiary (QMB)
- Social Security — Extra Help with Medicare prescription drug plan costs
- Arizona State Retirement System — Becoming Medicare eligible
- TRICARE — TRICARE For Life
Frequently asked questions
When should I sign up for Medicare if I turn 65 in Arizona?
If you don't have health coverage from your own or your spouse's current job, sign up in the 3 months before your birthday month so Part A and Part B start the first day of the month you turn 65. Signing up during your birthday month or the 3 months after is allowed, but coverage then starts the month after you sign up. If you already get Social Security, you are enrolled automatically.
Do I have to sign up for Medicare if I already get Social Security?
No. If you have been getting Social Security or Railroad Retirement benefits for at least 4 months before you turn 65, you are enrolled in Part A and Part B automatically and your card arrives about 3 months before your birthday month. If you have job-based coverage from current work and want to delay Part B, follow the instructions that come with the card.
Can I sign up for Medicare at a Social Security office in Arizona?
Yes. You can apply online at ssa.gov, call Social Security at 1-800-772-1213 (TTY 1-800-325-0778), or visit a local office. Use Social Security's office locator with your ZIP code to find the office that serves you and check whether you need an appointment.
When can I buy a Medigap policy in Arizona without health questions?
During your 6-month Medigap open enrollment period, which starts the first day of the month you are 65 or older and enrolled in Part B. Arizona has no birthday rule or yearly switching right, so after that window an insurer can ask health questions unless you have a federal guaranteed-issue right.
What happens if I skip Part D at 65?
If you go 63 days or more in a row without Part D or other creditable drug coverage after your Initial Enrollment Period ends, you may owe a late enrollment penalty when you join later. It is 1% of the national base beneficiary premium ($38.99 in 2026) for each full month without coverage, added to your premium for as long as you have Part D.
I'm retiring from the State of Arizona. What do I need at 65?
To join the Arizona State Retirement System's plans for Medicare-eligible retirees, ASRS says you must enroll in and keep both Part A and Part B. Retiree coverage doesn't let you delay Part B without a penalty, so plan your Medicare start date with your retirement date. Check the current ASRS enrollment guide before you decide.
Medicare in your Arizona county
Plans, local agents and help, county by county: Apache · Cochise · Coconino · Gila · Graham · Greenlee · La Paz · Maricopa · Mohave · Navajo · Pima · Pinal · Santa Cruz · Yavapai · Yuma
