A Medicare Premium Bill (form CMS-500) comes in the mail when you owe a Medicare premium that cannot be taken out of a Social Security or Railroad Retirement Board check. The usual reason is simple: you signed up for Part B but are not collecting Social Security yet. Part B is billed every 3 months, and every bill is due on the 25th. In 2026 the standard Part B premium is $202.90 a month, so a full quarterly bill is $608.70. If you stop paying, a "Delinquent Bill" with a termination date arrives once you are about 90 days behind, and your coverage ends if the full balance is not paid by that date.
This page explains why the bill came, what each charge means, how to pay it, how to make it stop, and exactly what happens if you miss payments.
Why You Got a Medicare Premium Bill
Most people never see a CMS-500. Their Part B premium is taken out of their monthly Social Security or Railroad Retirement benefit before the money reaches them. Medicare only mails a bill when there is no benefit check to take it from.
The people who get one usually fall into these groups:
| Your situation | Why Medicare bills you |
|---|
| You took Medicare at 65 but are waiting to claim Social Security (for example, until your full retirement age or 70) | No Social Security check exists to deduct from |
| You retired early, have Part B, and live on savings or a pension | Same reason: no Social Security payment yet |
| Your Social Security payments are on hold (suspended) | Premiums cannot be withheld from a payment that is not being made |
| You buy Part A because you have fewer than 40 work quarters | Part A premiums are billed monthly if not deducted |
| You owe a Part D income surcharge (IRMAA) and get no Social Security | The surcharge goes to Medicare, not your drug plan, so it is billed |
Early retirees and people who delay Social Security to grow their monthly benefit are the biggest group. Delaying Social Security is often a smart move, but Medicare still needs its premium, so it bills you directly until your benefit starts.
If you are still working and just picked up Part B, read Medicare if you're still working before paying for coverage you may be able to delay without a penalty.
What Is on the Bill: 2026 Amounts
The CMS-500 has a "Summary Of Charges" table that lists each premium type, the months it covers, and any past-due amount. Here are the figures that can appear for 2026.
| Charge | 2026 amount | How often billed |
|---|
| Part B standard premium | $202.90 a month ($608.70 a quarter) | Every 3 months |
| Part B IRMAA (higher income) | Extra amount on top of $202.90, set by Social Security | Every 3 months, with Part B |
| Part B late enrollment penalty | 10% of the standard premium for each full 12 months you went without Part B when you should have had it | Every 3 months, with Part B |
| Part A premium (fewer than 30 work quarters) | $565 a month | Every month |
| Part A premium (30 to 39 work quarters) | $311 a month | Every month |
| Part D IRMAA (higher income) | Set by Social Security | Every month |
Sources: CMS fact sheet "2026 Medicare Parts A & B Premiums and Deductibles" and Medicare.gov's premium payment page.
About 2027: CMS announces the next year's Part B premium each fall, usually in November. As of November 12, 2026, CMS had not published the 2027 Part B premium, so $202.90 remains the current figure through December 31, 2026. When the new amount takes effect in January, your bill updates automatically. Projections online are estimates, not the premium. See our 2026 Part B premium guide for the full breakdown.
What is NOT on the CMS-500: your Part D drug plan premium, your Medicare Advantage plan premium, and your Medigap premium. Those come from the private insurance company that sells the plan. The Part D IRMAA line on the CMS-500 is a federal surcharge, not your drug plan's premium.
Who pays IRMAA
IRMAA applies when your modified adjusted gross income from two years earlier is above a threshold. For 2026, the first tier starts above $109,000 for a single filer and $218,000 for a married couple filing jointly, based mostly on your 2024 tax return. If your income dropped because you retired, you can ask Social Security to use a newer year with Form SSA-44. Brackets are in our 2026 IRMAA guide.
Why Your First Bill Is Higher Than Expected
The first CMS-500 often covers more than 3 months. Social Security's rules say the first notice covers from the first month you owe through the end of the third month after the billing month, so a first bill can cover 4 or more months. If your Part B start date was set in the past, the months between your start date and the first bill are added on.
A first bill of $811.60 is 4 months at $202.90, not a mistake. Check the "Coverage Periods" column to see which months you are paying for.
How Quarterly Billing Works
Part B premiums are billed 3 months at a time, and you pay ahead for those 3 months. Key dates:
- Due date: the 25th of the month. Medicare.gov says premiums are generally due the same month you get the bill.
- Send payment early: Medicare asks you to send payment at least 5 business days before the due date.
- Monthly billing: Social Security's rules allow monthly billing instead of quarterly if the quarterly amount is a hardship, but you must ask for it. Call 1-800-MEDICARE (1-800-633-4227) to ask about your options.
- Part A and Part D IRMAA bills come every month, not every 3 months.
What Happens If You Don't Pay
Medicare does not cancel you the day after a missed payment. It moves through stages, and the bill itself tells you which stage you are in.
| Stage | What you see | What it means |
|---|
| 1. Bill arrives | Normal CMS-500, due the 25th | Pay by the due date |
| 2. Payment missed | "Past Premium Due" line appears on the next bill | The unpaid amount is added to your new total |
| 3. About 90 days late | Bill says "DELINQUENT BILL" at the top and lists Coverage Termination Dates | Pay the full "Total Amount Due" by the "Due In Full By" date or coverage ends |
| 4. Not paid in full | Coverage ends on the termination date | You lose Part B (and Part A if you buy it), and you still owe the back premiums |
The rule behind this is in federal regulation 42 CFR 408.8: the grace period ends on the last day of the third month after the billing month, and the end of the grace period is the termination date if the overdue premiums are still unpaid. Weekends and holidays push the date to the next work day.
Partial payments may not save you
On a delinquent bill, paying part of the balance may not stop the termination. Social Security's rules say coverage still ends if more than $10 of the past-due amount is left unpaid. If you get a delinquent bill, pay the full "Total Amount Due."
What losing Part B costs you
Losing Part B is more than losing one premium. It causes other problems:
- Medicare Advantage requires Part A and Part B. Lose Part B and you lose your Advantage plan too.
- Medigap pays after Part B. A Medigap policy is built to cover what Part B leaves behind. Without Part B, it does not replace Part B. See how Medigap works.
- The debt stays. CMS states that you must still pay the total premium you owe after coverage ends.
- Getting back in takes time. You usually have to wait for the General Enrollment Period, January 1 to March 31. Coverage starts the month after you sign up.
- A late penalty is possible. Medicare's bill warns that re-enrolling later can mean a higher premium and a lifetime late enrollment penalty for Part B. Our late enrollment penalty guide shows the math.
Getting coverage back for "good cause"
If something outside your control kept you from paying, such as a hospital stay or a serious illness, Medicare can restore your coverage with no gap. Under 42 CFR 408.8(d), you must:
- Show good cause. This means a believable explanation that the missed payment came from conditions you had no control over or could not reasonably have expected.
- Pay all overdue premiums within 3 calendar months after the termination date.
Call Social Security at 1-800-772-1213 (TTY 1-800-325-0778) as soon as you know coverage ended. Simply forgetting to pay usually does not count as good cause.
How to Pay Your Medicare Premium Bill
Medicare accepts four payment methods. It does not take payments by phone.
| Method | How | Timing |
|---|
| Online at Medicare.gov | Log in, choose "Pay my premium now," pay by card, HSA card, or bank account (processed through Pay.gov) | Fastest; bank payments take about 5 business days |
| Medicare Easy Pay | Sign up in your Medicare account under "My Premiums," or mail form SF-5510 | Free automatic deduction around the 20th of each month; setup can take 6 to 8 weeks |
| Your bank's bill pay | Set up a payment to CMS Medicare Insurance through your bank | Your bank may charge a fee |
| Mail | Check, money order, or card payment with the coupon from your bill | Slowest |
Mail payments go to: Medicare Premium Collection Center, P.O. Box 790355, St. Louis, MO 63179-0355.
Tips for mailed payments:
- Include the payment coupon. Without it, your payment can be delayed.
- Write your Medicare Number on the check or money order.
- Sign the coupon if paying by card, or the payment is returned.
- Send one payment and one coupon per envelope.
Keep paying your bill another way while Easy Pay is being set up. Easy Pay covers future bills, not the setup period.
How to Stop Getting a Medicare Bill
You have three main ways to make the CMS-500 go away.
1. Start Social Security or Railroad Retirement benefits. Once your benefit begins, Medicare switches to taking the premium out of your check. You do not need to file anything extra for this. Whether to claim now or wait is a bigger decision about your lifetime income, so do not claim early just to avoid a bill.
2. Turn on Medicare Easy Pay. You still owe the premium, but it comes out of your bank account automatically, so a forgotten envelope cannot cost you your coverage.
3. Get help through a Medicare Savings Program. If your income and savings are limited, your state Medicaid office may pay your Part B premium through a Medicare Savings Program (QMB, SLMB, or QI). Once approved, the state pays Medicare directly and the bill stops. Income limits are in our Medicare Savings Programs guide. A free State Health Insurance Assistance Program (SHIP) counselor can help you apply.
Is Your Medicare Bill Real?
Scammers copy Medicare billing. A real CMS-500:
- Is titled "Medicare Premium Bill" with form number CMS-500 printed on it
- Lists your Medicare Number and coverage periods
- Has a return address at the Medicare Premium Collection Center in St. Louis
- Never asks you to pay by phone, gift card, or wire transfer
If anything looks wrong, call 1-800-MEDICARE (TTY 1-877-486-2048) using the number you look up yourself, not one on a suspicious letter or caller ID.
Frequently Asked Questions
Why am I getting a bill for Medicare when I thought it was free?
Part A is premium-free for most people with 40 work quarters, but Part B always has a premium ($202.90 a month in 2026 for most people). If you are not collecting Social Security, Medicare cannot deduct it, so it sends a CMS-500 bill instead.
How often does the Medicare premium bill come?
The Part B bill comes every 3 months. Part A premium bills and Part D IRMAA bills come every month. All Medicare bills are due on the 25th.
What is the grace period for a Medicare premium bill?
Under 42 CFR 408.8, the grace period runs through the last day of the third month after the billing month. If you are about 90 days behind, your bill says "DELINQUENT BILL" and shows the date your coverage will end if you do not pay the full balance.
Will Medicare cancel me for one late payment?
No. A single late payment is added to your next bill as a past-due amount. Coverage ends only if you stay behind long enough to get a delinquent bill and then fail to pay the full balance by its due date.
Can I pay my Medicare premium bill over the phone?
No. CMS states that phone payments are not accepted. Pay online through your Medicare account, with Medicare Easy Pay, through your bank's bill pay, or by mail.
Does the CMS-500 include my Part D or Medigap premium?
No. Your Part D plan, Medicare Advantage plan, and Medigap insurer bill you separately. The CMS-500 covers Part A, Part B, Part B penalties, and the Part B and Part D IRMAA surcharges.
What happens to an overpayment?
CMS applies extra money first to any past-due balance, then to Part B and Part A, and last to Part D IRMAA. You cannot choose how an overpayment is applied.
What will the Part B premium be in 2027?
CMS had not published the 2027 Part B premium as of November 12, 2026. It announces the amount each fall. Until January 1, 2027, the standard premium is $202.90 a month.
Who do I call about my Medicare premium bill?
For billing questions, call 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048. For questions about your Part A or Part B enrollment, IRMAA, or getting coverage back after termination, call Social Security at 1-800-772-1213, TTY 1-800-325-0778.
