Key Takeaways

• Being enrolled in a PSHB plan does not automatically mean you don’t need Medigap. In fact, once you’re in PSHB and eligible for Medicare, certain gaps in your coverage may become more noticeable.

• The longer you delay the Medigap decision after enrolling in Medicare, the more complicated—and potentially costly—it can become due to underwriting and limited enrollment rights.

Why This Question Becomes Urgent After PSHB Enrollment

You may have chosen a Postal Service Health Benefits (PSHB) plan expecting it to cover your needs well into retirement. However, once you become eligible for Medicare—typically at age 65—you’ll notice that your PSHB plan starts to interact with Medicare differently. The urgent question then becomes: Do you also need a Medigap policy?

This isn’t a question you can afford to put off. While your PSHB plan may offer generous coverage, it does not always fill all the gaps that Medicare leaves behind, especially if you didn’t enroll in Medicare Part B or if your provider network is limited.

Let’s walk through what changes once you’re in both Medicare and PSHB, and why Medigap might suddenly become relevant—fast.

Understanding the PSHB and Medicare Interaction

Once you enroll in Medicare, your PSHB plan becomes secondary in most cases, especially when you’re enrolled in both Medicare Part A and Part B. Here’s what that usually means:

• Medicare pays first.

• Your PSHB plan pays second, often covering some or all of the remaining costs.

However, there are limits:

• Some PSHB plans only coordinate benefits fully if you’re enrolled in both Part A and Part B.

• Not all services are covered 100%, even with both Medicare and PSHB.

• Coinsurance and deductibles may still apply, especially for extended hospital stays or outpatient services.

Why Medigap Might Be the Missing Piece

Medigap, also known as Medicare Supplement Insurance, is designed to pay for what Medicare doesn’t. This includes:

• Coinsurance and copayments for Medicare-covered services

• Hospital costs after Medicare benefits are exhausted

• Some skilled nursing facility care

• Foreign travel emergency care (in limited cases)

Even though your PSHB plan may offer some of these benefits, gaps remain. For example, your PSHB plan might not fully waive Medicare deductibles or cover every specialist you need. If your health situation changes—like requiring long-term specialist care or hospitalization—the cracks in coverage can start to widen.

Enrollment Timing and Restrictions

The urgency becomes even clearer once you understand how Medigap enrollment works:

• You get a six-month Medigap Open Enrollment Period that starts when you are both 65 or older and enrolled in Medicare Part B.

• During this period, you can buy any Medigap policy available in your state without medical underwriting.

• Once that window closes, you may be denied coverage or charged more based on health status.

If you already enrolled in PSHB thinking you didn’t need Medigap, and now realize you do—but your six-month window has passed—your options may be more limited.

What PSHB Doesn’t Do That Medigap Can

PSHB plans offer broad coverage, but they aren’t designed to:

• Fully replace the financial protection of a Medigap plan

• Be used as a substitute for Medicare Part B (especially since some PSHB plans reduce their benefits if you don’t enroll in Part B)

• Offer standard cost-sharing predictability across plans like Medigap does

Medigap is built around filling the standardized gaps in Medicare. PSHB is built around being a comprehensive health plan. These goals don’t always align perfectly once Medicare becomes your primary payer.

Why Coordination Gets Complicated

With PSHB and Medicare in play, coordination of benefits is not automatic in every case. Things that can trip you up include:

• Going out of network under your PSHB plan

• Not having Medicare Part B when it’s required for full coordination

• Getting care from a provider who accepts Medicare but not your PSHB plan

In these situations, Medigap can help stabilize your out-of-pocket costs by paying the amounts Medicare doesn’t cover, regardless of your PSHB network rules.

Medicare Part B Enrollment Affects Everything

One of the most overlooked details is how crucial Medicare Part B enrollment is to your overall coverage:

• Most PSHB plans assume you’ll enroll in Part B once eligible.

• If you decline Part B, your PSHB plan may increase your cost-sharing or reduce coordination.

• Without Part B, you can’t buy Medigap.

So if you’re in PSHB and nearing 65, delaying Part B can trigger a domino effect: limited PSHB benefits, no Medigap eligibility, and high out-of-pocket expenses.

You Can’t Rely on Just One Plan

The big mistake is assuming that either PSHB or Medigap is enough by itself. In truth:

• Medicare + PSHB may leave gaps if cost-sharing isn’t fully covered.

• PSHB alone is not intended to function without Medicare Parts A and B.

• Medigap can’t be used if you don’t have Medicare Parts A and B.

Therefore, the optimal structure often looks like this:

Medicare Part A + Part B + PSHB + Medigap (if you expect high usage or want more predictable costs).

That might sound like a lot, but not every plan or person needs this combination. Still, it’s worth evaluating early—ideally before your Part B enrollment window closes.

Waiting Could Cost You More Than You Think

If you wait too long to ask the Medigap question, you might face:

• Medical underwriting that leads to denial or high premiums

• Reduced PSHB coordination if you delay Medicare Part B

• Surprise costs for hospital stays, durable medical equipment, or specialist visits

The timing issue isn’t just about cost—it’s about access. Once the Medigap enrollment window closes, there’s no guarantee you’ll be able to get in later, especially if your health declines.

What to Do If You’ve Already Missed the Medigap Window

If you’re in PSHB, enrolled in Medicare, and missed the Medigap open enrollment, you still have a few options:

• Check whether your state offers special enrollment protections

• Review your current PSHB plan’s coordination features

• Speak with a licensed agent to understand if underwriting might still allow Medigap enrollment

• Explore whether a different PSHB plan might offer better Medicare integration

The key is to act sooner rather than later. Every month you wait narrows your options.

Making a Forward-Looking Strategy

Here’s how to approach the Medigap decision once you’re in PSHB:

• At age 64: Start reviewing your Medicare and Medigap options alongside your PSHB plan.

• At Medicare Part B enrollment: Decide whether Medigap is right for you within the 6-month window.

• Each year during Open Season: Reassess your PSHB plan to ensure it still complements your Medicare coverage.

You’re not locked into one strategy forever—but the window for making the easiest and most cost-effective decisions doesn’t stay open long.

PSHB and Medigap Together Require Smart Planning

The overlap between PSHB and Medigap isn’t always obvious. Many Postal retirees and annuitants only start asking the right questions once they run into coordination problems or unexpected costs.

Don’t wait for that to happen. Use your Medicare eligibility as a cue to re-evaluate everything—even if you thought PSHB was enough. You might discover that Medigap is exactly what was missing all along.

If you’re unsure, the best step is to get in touch with a licensed agent listed on this website. They can walk you through your specific eligibility, timelines, and how to avoid costly mistakes.