Key Takeaways

• Missing your Medicare Part B enrollment deadline could cause your entire PSHB health coverage to collapse or become far more expensive than expected.

• If you are required to enroll in Medicare Part B and fail to do so, you may lose drug coverage, face late penalties, and experience higher out-of-pocket costs under your PSHB plan.

Understanding the Part B Requirement in the PSHB Program

The Postal Service Health Benefits (PSHB) program, introduced in 2025, is now the mandatory health coverage for USPS employees, annuitants, and their eligible family members. If you’re eligible for Medicare, PSHB doesn’t function independently. It often depends on whether or not you are enrolled in Medicare Part B.

The PSHB Program integrates closely with Medicare. In fact, certain PSHB plans require you to be enrolled in Medicare Part B to maintain full coverage. This integration is meant to reduce your costs and expand your benefits—but it also means a missed enrollment deadline could trigger a domino effect of coverage issues.

Who Must Enroll in Medicare Part B?

As of 2025, the following PSHB participants are generally required to enroll in Medicare Part B:

• USPS annuitants entitled to Medicare Part A who retired after January 1, 2025

• Eligible family members of those annuitants

• Active employees who were younger than 64 on January 1, 2025, once they retire and become entitled to Medicare

Exemptions exist, such as for those who retired on or before January 1, 2025, or who are enrolled in other qualifying coverage such as VA benefits. But if you’re not exempt and you miss your Medicare Part B enrollment period, your PSHB coverage could face serious disruption.

What Happens When You Miss the Deadline

Failing to enroll in Medicare Part B by the deadline doesn’t simply result in a late fee. It may undermine the core of your PSHB plan.

Here’s what you risk losing or facing:

• Loss of PSHB prescription drug coverage if you’re Medicare-eligible and not enrolled in Part B, since most drug coverage is now provided through a Medicare Part D plan embedded in your PSHB coverage.

• No access to Part B premium reimbursements or cost-sharing reductions offered by certain PSHB plans.

• Higher deductibles and coinsurance because your PSHB plan will assume Medicare is the primary payer, even if you’re not enrolled.

• Delayed coverage due to limited enrollment periods, forcing you to wait months without adequate protection.

• Late enrollment penalties that permanently increase your monthly Part B premium.

Enrollment Windows You Can’t Afford to Miss

Your Initial Enrollment Period (IEP) for Medicare Part B begins three months before your 65th birthday and ends three months after, totaling seven months. If you miss this window, you can only sign up during the General Enrollment Period (GEP) between January 1 and March 31 each year—with coverage beginning July 1.

That gap can expose you to months without critical coverage. For PSHB members who require Part B, this is especially risky. During that coverage gap, you might:

• Have no prescription drug benefits

• Be billed at full cost for outpatient services

• Miss cost-sharing protections that your PSHB plan otherwise provides

The Role of Special Enrollment Periods

Some beneficiaries qualify for a Special Enrollment Period (SEP). For PSHB members, an SEP was available in 2024 for those who were Medicare-eligible but hadn’t enrolled in Part B. That SEP ended on September 30, 2024. As of now, no equivalent SEP is active, which means you must adhere strictly to the IEP or GEP.

If you’re waiting for another SEP to come around, that could be a costly gamble. There’s no guarantee another special opportunity will be offered for PSHB-specific enrollees.

How Missing Part B Impacts Your Prescription Drug Coverage

If you’re eligible for Medicare and remain enrolled in a PSHB plan without enrolling in Part B, you are typically automatically opted out of the Medicare Part D prescription drug benefit built into the PSHB plan.

This means:

• You lose access to PSHB drug coverage entirely

• You may not be allowed to re-enroll in the plan’s Part D coverage later

• You will need to find and pay for drug coverage separately, which may not be as comprehensive

The PSHB system does not allow you to keep the drug portion if you opt out of Part B. This tight link between Part B and prescription benefits is easy to overlook until you face the out-of-pocket costs.

Penalties That Don’t Expire

Missing your Medicare Part B enrollment not only disrupts your PSHB coverage—it could cost you more for the rest of your life. The Part B late enrollment penalty adds 10% for every full 12-month period you were eligible and didn’t sign up.

For example, if you waited 24 months, you’ll pay 20% more for Part B—for as long as you have Medicare. Since most retirees are on a fixed income, these extra charges can strain your finances permanently.

The Part D penalty is equally harsh. If you go more than 63 days without creditable prescription drug coverage, you may owe a penalty on your drug plan premium, also for life.

Your PSHB Plan Assumes You Have Part B

What makes this situation especially tricky is how PSHB plans coordinate benefits. Once you’re eligible for Medicare, your PSHB plan becomes secondary to Medicare.

But if you don’t enroll in Part B, PSHB still behaves as if Medicare is your primary payer. That means:

• The PSHB plan pays less than it normally would

• You are stuck with the difference

• You may have to pay out-of-pocket for services Medicare Part B would have covered first

In other words, PSHB assumes you’re fulfilling your Medicare obligations, and won’t protect you if you’re not.

You Won’t Always Get a Reminder

You might assume you’ll get a clear notification when it’s time to enroll in Medicare Part B. But that’s not always the case.

• The Social Security Administration handles Medicare enrollment, not OPM or USPS

• You may get letters from both, or neither

• If you overlook one mailed notice or misread your Open Season materials, you could miss your enrollment window without realizing it

This makes it critical to proactively track your eligibility and timelines. Don’t wait for a formal notice—create calendar reminders and consult your PSHB plan documents regularly.

What You Can Do If You’ve Already Missed It

If you’ve missed the IEP and SEP, your next opportunity is the General Enrollment Period from January 1 to March 31. However, your coverage won’t begin until July 1—leaving you months exposed.

During this time, you may be:

• Denied drug benefits from PSHB

• Billed in full for outpatient visits

• Responsible for uncovered costs due to primary/secondary payer issues

If you’re in this position now, consider:

• Calling your PSHB plan’s customer service line to confirm what coverage remains

• Reviewing your eligibility for any active SEPs (such as loss of employer coverage)

• Preparing to enroll at the next GEP, and budgeting for uncovered care in the interim

Don’t Assume Your PSHB Coverage Is Enough on Its Own

Because PSHB is tailored to USPS employees and retirees, it feels like it should cover everything once you retire. But that’s not the case for those turning 65.

Here’s what PSHB doesn’t do if you skip Medicare Part B:

• Cover outpatient surgeries fully

• Provide prescription drug coverage

• Waive deductibles or coinsurance that would have been eliminated by Medicare

Assuming your PSHB plan will take over completely can lead to devastating surprise bills and unpaid claims.

Protect Your Health—and Your Wallet—With a Timely Decision

Missing the Medicare Part B enrollment window can fracture your PSHB coverage, increase your healthcare expenses, and reduce your access to benefits you counted on. The integration between PSHB and Medicare is strong, but only if you meet your enrollment requirements.

If you’re approaching 65 or are already eligible for Medicare, review your PSHB plan details immediately. Check your eligibility status, note enrollment deadlines, and don’t leave it to chance.

Speak with a licensed agent listed on this website to confirm your responsibilities, avoid permanent penalties, and ensure your PSHB plan delivers everything it’s designed to.