Medigap vs Part D
Medigap (Medicare Supplement) and Part D drug plan (standalone) 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, Standalone Part D plans cover outpatient prescriptions for beneficiaries on Original Medicare. The right plan is the one that covers your drugs at the lowest total annual cost at your pharmacies. 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-$100+/mo before Extra Help |
| 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). | Medicare enrollment rules apply. |
| Best for | People who want predictable costs; Frequent travelers; Those who want any-provider access | Original Medicare beneficiaries; Anyone comparing drug-only costs |
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
Standalone Part D plans cover outpatient prescriptions for beneficiaries on Original Medicare. The right plan is the one that covers your drugs at the lowest total annual cost at your pharmacies.
Pros
- Drug-focused shopping
- Can change yearly
- Extra Help may lower costs
Cons
- Formulary changes
- Pharmacy networks
- Separate from medical coverage
Frequently asked questions
- Is Medigap or Part D cheaper?
- Part D typically has the lower monthly cost (approx. $0-$100+/mo before extra help), 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 coverage paired 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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