Medicare 2026

Plainfield guide to Medicare Part B and Part D penalties: how the math works

Plainfield, Ill. — Most Medicare mistakes can be fixed the next year. Missing your Part B or Part D enrollment window is not one of them. Sign up late without the right kind of coverage in place, and the surcharge can follow you for the rest of your life.

Medicare 2027Plainfield, IL

Here is how the two penalties actually work, how Plainfield residents can avoid them, and where to get free local help before you make a decision you cannot easily undo.

How the Part B penalty works

Part B covers doctor visits, outpatient care and many preventive services. If you do not sign up when you are first eligible — and you do not have other coverage that Medicare accepts as a valid reason to delay — you can be charged a late enrollment penalty.

The penalty is 10% added to your standard Part B premium for each full 12-month period you could have had Part B but did not. That extra amount is not a one-time fee. In most cases, you pay it every month for as long as you have Part B.

Your Initial Enrollment Period is a seven-month window: the three months before the month you turn 65, your birthday month, and the three months after.

How the Part D penalty works

Part D covers prescription drugs. The penalty here is calculated differently. Medicare multiplies 1% of the "national base beneficiary premium" by the number of full months you went without Part D or other creditable drug coverage after you were first eligible.

That amount is rounded and added to your Part D premium every month you have a drug plan. Like the Part B penalty, it generally sticks with you.

"Creditable coverage" is a key phrase. It means drug coverage that is expected to pay, on average, at least as much as standard Medicare Part D. Employer plans, union plans and some retiree plans often qualify. Your plan is required to send you a notice each year telling you whether your coverage is creditable — keep those letters.

How Plainfield residents can avoid both penalties

There are three common ways to stay penalty-free:

1. Enroll during your Initial Enrollment Period. For most people, that is around your 65th birthday. 2. Keep creditable coverage and enroll later through a Special Enrollment Period. If you or your spouse are still working and covered by a qualifying employer plan, you generally have eight months after that coverage ends to sign up for Part B without a penalty, and about two months to pick up Part D. 3. Do not let gaps stretch out. Even a few months without creditable drug coverage can add to a Part D penalty later.

Plainfield is in Will County, and plan availability — Medicare Advantage, Part D, and Medigap — is set at the county level. That affects the choices you have, but it does not change the penalty rules, which are federal.

Dates worth writing down

• Initial Enrollment Period: the seven months around your 65th birthday.
• General Enrollment Period: Jan. 1 – March 31, for people who missed their initial window.
• Annual Enrollment Period: Oct. 15 – Dec. 7, when you can join, switch or drop Medicare Advantage and Part D plans.
• Medicare Advantage Open Enrollment: Jan. 1 – March 31, for people already in a Medicare Advantage plan.

The Part D maximum deductible is $615 in 2026 and $700 in 2027. The annual cap on what you pay out of pocket for covered drugs is $2,100 in 2026 and $2,400 in 2027. The old coverage gap, or "donut hole," was eliminated in 2025, so Part D now has three phases instead of four. A separate program, the Medicare Prescription Payment Plan, lets you spread your drug costs across the year in monthly amounts if you want to.

Higher-income beneficiaries may also pay an IRMAA surcharge on Part B and Part D. For 2026, that begins above $109,000 in income for a single filer.

Where to get free help in Plainfield

You do not have to figure this out alone, and you do not have to talk to a salesperson to get answers. Illinois runs a free State Health Insurance Assistance Program (SHIP) with trained counselors who can walk you through your specific situation, including whether your current coverage counts as creditable.

You can also compare plans and check your enrollment status directly at medicare.gov, or call 1-800-MEDICARE (1-800-633-4227), which is available 24 hours a day, seven days a week.