Medigap vs Part D
Medigap (Medicare Supplement) and Medicare Part D (Drug Plan) solve the same problem in different ways. Medigap policies supplement Original Medicare by covering much of its cost sharing — deductibles, copays, and coinsurance — so you get highly predictable costs and can see any provider that accepts Medicare nationwide, with no networks. Plans are standardized by letter (e.g. Plan G, Plan N), so the difference between carriers for the same letter is price and service. Medigap does not include drug coverage, so you add a standalone Part D plan. By contrast, Part D is prescription drug coverage sold by private insurers to pair with Original Medicare (and Medigap). Each plan has its own formulary, pharmacy network, and tiers, so the right plan depends on your specific medications. Recent law caps annual out-of-pocket drug spending, a meaningful protection for people with high drug costs. Choosing Part D is a per-drug exercise, not a one-size-fits-all decision. Below we compare them on cost, coverage, eligibility, and who each one fits best — with sources you can check.
| Factor | Medigap | Part D |
|---|---|---|
| Typical monthly cost | Approx. $120-$300/mo depending on plan letter, age, and state | Approx. $0-$70/mo depending on the plan and your medications |
| Relative cost | $$· | $·· |
| Category | Medicare option | Medicare option |
| Is it insurance? | Yes | Yes |
| ACA-compliant major medical | Yes | No |
| Covers pre-existing conditions | Yes | Varies |
| Eligibility | Best bought during your Medigap Open Enrollment window (no health questions then). | Must have Medicare Part A and/or Part B. |
| Best for | People who want predictable costs; Frequent travelers; Those who want any-provider access | Anyone on Original Medicare who takes prescriptions; Medigap enrollees |
Medigap
Medigap policies supplement Original Medicare by covering much of its cost sharing — deductibles, copays, and coinsurance — so you get highly predictable costs and can see any provider that accepts Medicare nationwide, with no networks. Plans are standardized by letter (e.g. Plan G, Plan N), so the difference between carriers for the same letter is price and service. Medigap does not include drug coverage, so you add a standalone Part D plan.
Pros
- Predictable out-of-pocket costs
- Any Medicare provider, no network
- Standardized plans
Cons
- Higher premium than most Advantage plans
- No drug coverage
- Medical underwriting outside open enrollment
Part D
Part D is prescription drug coverage sold by private insurers to pair with Original Medicare (and Medigap). Each plan has its own formulary, pharmacy network, and tiers, so the right plan depends on your specific medications. Recent law caps annual out-of-pocket drug spending, a meaningful protection for people with high drug costs. Choosing Part D is a per-drug exercise, not a one-size-fits-all decision.
Pros
- Annual out-of-pocket drug cap
- Wide plan choice
- Pairs with Medigap
Cons
- Formularies differ
- Late-enrollment penalty if you delay
- Must match to your drug list
Frequently asked questions
- Is Medigap or Part D cheaper?
- Part D typically has the lower monthly cost (approx. $0-$70/mo depending on the plan and your medications), while Medigap runs higher (approx. $120-$300/mo depending on plan letter, age, and state). The cheaper option is not automatically better — weigh the coverage trade-offs below.
- What is the main difference between Medigap and Part D?
- A private policy that pays Original Medicare’s out-of-pocket costs for predictable bills nationwide. Standalone prescription drug coverage that pairs with Original Medicare or Medigap.
- Can I switch between Medigap and Part D?
- Often yes, though timing rules apply. Comprehensive insurance changes usually happen during Open Enrollment or a Special Enrollment Period, so check the enrollment window before you switch.
Sources
- Medicare.gov — the official U.S. government Medicare site · reviewed 2026-01-15
- OLYRON HealthMatch editorial methodology — how we source and rate options · reviewed 2026-01-15
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