Medicare Supplement vs. Medicare Advantage — Washington State Guide

Two Approaches

What are your two main options for Medicare coverage?

When you become eligible for Medicare, you face a fundamental choice: stick with Original Medicare and add a Medigap supplement plan, or switch to a Medicare Advantage plan. Each approach has different costs, coverage structures, and provider networks. Neither is universally better — the right choice depends on your healthcare needs, budget, and preferences.

This is one of the most important healthcare decisions you will make in retirement, and it directly affects your retirement income planning because healthcare costs are typically the largest expense category for retirees after housing.

Comparison

How do Medigap and Medicare Advantage compare?

Medigap plans offer broader provider access and more predictable costs but at higher monthly premiums. Medicare Advantage plans offer lower premiums and often include extras like dental and vision, but use provider networks and may have higher costs when you use care.

Feature	Original Medicare + Medigap	Medicare Advantage
Monthly premium	Higher (Part B + Medigap + Part D)	Often $0–$50 (includes coverage)
Out-of-pocket costs	Low and predictable	Copays and coinsurance per service
Doctor choice	Any doctor accepting Medicare	Network-based (HMO/PPO)
Prescription drugs	Separate Part D plan needed	Usually included
Extra benefits	None	Often dental, vision, hearing, gym
Referrals needed	No	May need referrals (HMO)
Out-of-pocket maximum	None (but costs are low)	Required by law (varies by plan)

Plan availability, costs, and benefits vary by county, carrier, and year. This comparison reflects general characteristics as of 2026. Review specific plan details during your enrollment period.

Washington State

What should Washington state residents know?

Washington has strong consumer protections for Medigap enrollees. During your open enrollment period, no insurer can deny you a Medigap policy or charge more based on health conditions. Washington also has a good selection of both Medigap and Medicare Advantage plans across most counties.

If you live in the Spokane metro area, Liberty Lake, or Northern Idaho, check which Medicare Advantage plans include your preferred doctors and hospitals in their network. Provider networks can vary significantly between plans, and a plan that works well in downtown Spokane may have gaps in rural areas.

Ben Volk is licensed to help with Medicare Supplement plans in Washington and can compare options from multiple carriers. For Medicare Advantage plan comparisons, medicare.gov is the official resource.

Common questions

What is the difference between Medicare Supplement and Medicare Advantage?+

Medicare Supplement (Medigap) is additional coverage that fills the gaps in Original Medicare (Parts A and B). Medicare Advantage (Part C) is an alternative to Original Medicare offered by private insurers that bundles hospital, medical, and usually prescription drug coverage into one plan.

Can I have both a Medigap plan and a Medicare Advantage plan?+

No. You cannot have both at the same time. You choose one approach: Original Medicare + Medigap supplement, or Medicare Advantage. You can switch during annual enrollment periods.

When should I enroll in a Medigap plan?+

The best time is during your Medigap open enrollment period, which starts the month you turn 65 and are enrolled in Medicare Part B. During this 6-month window, insurers cannot deny you coverage or charge higher premiums based on health conditions.

Do Medicare Supplement plans cover prescription drugs?+

No. Medigap plans do not cover prescription drugs. You need a separate Part D plan for drug coverage. Medicare Advantage plans typically include drug coverage.

Which costs more: Medigap or Medicare Advantage?+

Medigap plans have higher monthly premiums but lower out-of-pocket costs when you use care. Medicare Advantage plans often have low or $0 premiums but may have copays, coinsurance, and network restrictions when you receive services.

Can I see any doctor with a Medicare Supplement plan?+

With Original Medicare + Medigap, you can see any doctor in the country who accepts Medicare. Medicare Advantage plans typically use networks (HMO or PPO), and going out of network may cost more or not be covered.

Medicare Supplement vs. Advantage: a Washington state guide.

What are your two main options for Medicare coverage?

How do Medigap and Medicare Advantage compare?

What should Washington state residents know?

Common questions

Have questions about your situation?