Part D vs Plan G
Medicare Part D (Drug Plan) and Medigap Plan G solve the same problem in different ways. 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. By contrast, Medigap Plan G is a standardized supplement that works with Original Medicare to cover most Part A and B cost-sharing, typically leaving the Part B deductible as your main residual cost in current designs for new beneficiaries. Below we compare them on cost, coverage, eligibility, and who each one fits best — with sources you can check.
| Factor | Part D | Plan G |
|---|---|---|
| Typical monthly cost | Approx. $0-$70/mo depending on the plan and your medications | Approx. $100-$250/mo depending on age, state, and tobacco status |
| Relative cost | $·· | $$$ |
| Category | Medicare option | Medicare option |
| Is it insurance? | Yes | Yes |
| ACA-compliant major medical | No | No |
| Covers pre-existing conditions | Varies | Varies |
| Eligibility | Must have Medicare Part A and/or Part B. | Guaranteed issue during Medigap open enrollment in most cases. |
| Best for | Anyone on Original Medicare who takes prescriptions; Medigap enrollees | Travelers wanting nationwide access; People who want predictable costs |
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
Plan G
Medigap Plan G is a standardized supplement that works with Original Medicare to cover most Part A and B cost-sharing, typically leaving the Part B deductible as your main residual cost in current designs for new beneficiaries.
Pros
- Predictable coverage
- Nationwide Medicare access
- Standardized benefits
Cons
- Higher premium than many Advantage plans
- No extras like dental/vision built in
- Underwriting may apply outside OE
Frequently asked questions
- Is Part D or Plan G cheaper?
- Part D typically has the lower monthly cost (approx. $0-$70/mo depending on the plan and your medications), while Plan G runs higher (approx. $100-$250/mo depending on age, state, and tobacco status). The cheaper option is not automatically better — weigh the coverage trade-offs below.
- What is the main difference between Part D and Plan G?
- Standalone prescription drug coverage that pairs with Original Medicare or Medigap. Popular Medigap letter covering most Original Medicare cost-sharing.
- Can I switch between Part D and Plan G?
- 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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