Why It’s Risky to Assume Every Medicare Part C Plan Covers What You Need

Key Takeaways

• Medicare Part C plans (Medicare Advantage) do not all offer the same coverage or access to providers, and assuming they do can lead to major gaps in your healthcare benefits.

• If you’re a Postal Service Health Benefits (PSHB) enrollee, you must carefully assess what each Medicare Advantage plan includes, especially if you also have or are considering coordination with your PSHB plan.

What Medicare Part C Actually Covers

Medicare Part C, also called Medicare Advantage, is an alternative to Original Medicare that combines Part A (hospital insurance) and Part B (medical insurance), and often includes additional benefits like dental, vision, and hearing. In 2025, these plans continue to be offered by private companies that contract with Medicare.

But here’s the catch: even though they are required to cover everything Original Medicare does, they are not required to cover it the same way. Each plan sets its own rules, including provider networks, referral requirements, prior authorizations, and out-of-pocket costs.

Not All Part C Plans Are the Same

One of the biggest misconceptions is that all Medicare Advantage plans work similarly. In reality, plans differ by:

• Network size and structure: Some have tight provider networks, like HMOs, while others (PPOs) offer broader access.

• Service areas: Plans are regionally based. You may lose coverage or face restrictions if you travel or move.

• Cost structure: Premiums, deductibles, copayments, and out-of-pocket maximums vary widely.

• Supplemental benefits: Dental, vision, hearing, and fitness programs are not guaranteed and differ plan to plan.

As a result, the benefits and limitations you receive depend heavily on your chosen plan and your geographic location. Assuming that any Part C plan will match what you have under PSHB or Original Medicare can lead to costly surprises.

The Risk of Incomplete Provider Access

One of the most overlooked issues is provider access. Many Medicare Advantage plans use restricted networks. That means:

• Your current doctor may not be in-network

• You may need a referral to see a specialist

• Some hospitals may be out-of-network entirely

This matters greatly if you’re used to the flexibility of PSHB, where many plans allow nationwide provider access. Once you switch to a Medicare Advantage plan with a narrow network, you could be limited in both emergency and non-emergency care.

Prior Authorization Requirements

Another concern with Part C plans is the growing use of prior authorization. While Original Medicare rarely requires this, Medicare Advantage plans may ask you to get approval before:

• Undergoing imaging procedures (like MRIs or CT scans)

• Being referred to a specialist

• Receiving home health care

• Admitting to skilled nursing facilities

This can delay necessary care, especially if you need frequent specialist services or have chronic conditions that require ongoing treatments.

How Cost-Sharing Can Get Complicated

Every Medicare Advantage plan has an out-of-pocket maximum. In 2025, the maximum allowed for in-network services is $9,350, but this is just the ceiling. Many plans have lower limits. However, here’s where the assumption gets risky:

• Copays and coinsurance can differ greatly

• Tiered networks may charge more for some providers

• Out-of-network services (if allowed) often have higher costs or separate deductibles

If you’re coordinating with PSHB, your out-of-pocket responsibilities could be unpredictable unless the plan clearly outlines how your benefits will align.

Part D Drug Coverage Isn’t Always Straightforward

Many Medicare Part C plans include prescription drug coverage (MAPD plans). But:

• Not all formularies are the same

• Medications may fall under different tiers, affecting costs

• Some plans require step therapy before approving more expensive medications

PSHB enrollees eligible for Medicare are typically enrolled automatically into a Medicare Part D EGWP plan through PSHB. Opting into a Part C plan that includes Part D can disrupt this coordination and result in loss of your PSHB prescription drug benefit.

Travel and Emergency Coverage Limitations

If you travel often or live in multiple locations throughout the year, you need to consider how Medicare Advantage will treat out-of-area services. Many plans do not cover non-emergency services outside your service area.

Even emergency coverage can be tricky. Some plans will cover ER visits out of state but not urgent care or follow-up visits. That’s a stark contrast to PSHB plans, many of which provide broad national access and consistency.

PSHB and Medicare Part C: Coordination Challenges

As a Postal retiree or employee, your PSHB plan is tailored to coordinate with Medicare. In 2025, Medicare Part B enrollment is required for certain annuitants to keep PSHB coverage. Most PSHB plans are structured to work seamlessly with Original Medicare (Parts A and B), often reducing out-of-pocket costs when both are in place.

However, when you choose Medicare Advantage instead of Original Medicare:

• PSHB becomes your secondary coverage, if at all

• Some PSHB plans may not coordinate at all with Part C plans

• You could be paying premiums for PSHB benefits you can’t fully use

That means you might lose access to cost-sharing benefits like waived deductibles, coinsurance reductions, or premium reimbursement benefits that PSHB plans offer when paired with Original Medicare.

Enrollment Windows and Commitment Periods

Another risk is in the timing. Medicare Advantage enrollment is typically only allowed:

• When you first become eligible for Medicare

• During the Annual Enrollment Period (October 15 to December 7)

• During the Medicare Advantage Open Enrollment Period (January 1 to March 31, for existing enrollees only)

If you choose a Part C plan and later regret it, you may be stuck with it for the rest of the year. This is especially risky if you assumed your plan would cover services or medications it does not.

What You Can Do to Protect Yourself

To make a truly informed decision, you need to:

• Check provider directories carefully to ensure your doctors and hospitals are covered

• Review the drug formulary to confirm your medications are included at a reasonable tier

• Understand the plan’s cost-sharing rules beyond premiums, including copays, deductibles, and annual caps

• Know how PSHB coordinates with the plan

• Consider out-of-network costs and travel limitations

• Ask about supplemental benefits and whether they’re included or cost extra

Medicare Part C Isn’t Always the Better Value

Although some enrollees are drawn to Medicare Advantage due to potential lower premiums and added extras, these benefits can mask significant limitations. When stacked against the broad, stable coverage of PSHB and Original Medicare, especially for retirees with complex medical needs or frequent travel, Medicare Part C might not be as attractive as it first appears.

If you rely on consistent access to providers, clear coordination of benefits, and reduced administrative friction, sticking with Original Medicare plus PSHB might be the more stable path.

Making the Right Decision as a PSHB Enrollee

In 2025, as a PSHB enrollee, you have access to robust healthcare options. However, Medicare Part C should not be treated as a one-size-fits-all alternative. You need to look past the surface.

Before making any coverage decisions:

• Review your Annual Notice of Change (ANOC) each fall

• Consider your current and expected medical needs for the year ahead

• Examine how Medicare Part B and PSHB coordinate compared to Medicare Part C

• Assess whether the restrictions of Medicare Advantage fit your lifestyle

It’s tempting to switch plans based on short-term advantages, but in the long term, failing to account for network restrictions, prior authorization policies, and coordination issues can cost more — both financially and in terms of your health outcomes.

How to Move Forward Confidently

Choosing the right Medicare path requires careful evaluation of your personal circumstances, medical needs, and the structure of your PSHB benefits. Misjudging what a Medicare Part C plan covers can leave you without the access or cost protections you counted on.

If you’re unsure which route to take, get in touch with a licensed agent listed on this website. They can explain how different coverage options work with PSHB, and help you understand the full picture before you enroll.