Medicare Part C vs Medigap: Costs, Coverage, and Real 2025 Scenarios
12/08/2025
Estimated reading time: 7 minutes
Choosing between Medicare Part C and Medigap can feel overwhelming. Many people are confused by the differences between Medicare Part C vs Medigap, especially regarding coverage, costs, networks, and enrollment rules.
This guide provides a data-driven comparison to help you make an informed decision about which option best fits your healthcare needs and budget.
“Understanding the coverage differences is the crucial first step in choosing between Medicare Part C and Medigap.”
Medicare Advantage vs Medigap Cost Comparison
Annual Cost Comparison
When comparing costs between Medicare Advantage and Medigap, consider your total annual expenses:
Medicare Advantage, Part C:
Monthly premium, often 0 dollars.
Copays and coinsurance when you receive services.
Deductibles for medical and possibly drug coverage.
All costs capped by the out-of-pocket maximum, 9,350 dollars in 2025.
Medigap:
Monthly Medigap premium, typically higher than Advantage.
Part B premium.
Part B deductible, with Plan G.
Separate Part D premium and drug costs.
Few unexpected costs for covered services depending on plan letter.
The right choice depends on your health needs, budget, and preferences for predictability versus potentially lower upfront costs. As you weigh these decisions, consider how AI is playing a role in financial planning. See Make Better Decisions with AI: Virtual Assistants for Life’s Big Choices.
[Source: Medicare Advantage vs Medigap Video]
Medigap Plan G Cost 2025
Plan G has become one of the most popular Medigap options because:
Plans C and F are not available to people new to Medicare after January 1, 2020.
Plan G covers all the same benefits as Plan F except the Part B deductible.
It offers comprehensive coverage with predictable costs.
Plan G premiums in 2025 vary significantly based on:
Your age.
Your location, state and county.
The insurance company you choose.
Whether the plan uses attained-age, issue-age, or community-rated pricing.
Monthly premiums typically range from 100 to 300 dollars or more depending on these factors.
Consider these factors when calculating your potential annual costs:
For Medicare Advantage:
Monthly premium.
Expected doctor visits with copays.
Potential hospital stays.
Prescription drug needs.
Estimated annual out-of-pocket spending.
For Medigap plus Part D:
Medigap monthly premium.
Part B deductible, with Plan G.
Part D plan premium.
Expected prescription drug costs.
For many people, Medigap has higher predictable monthly costs and fewer unexpected expenses at the point of service, while Advantage plans often have lower premiums and variable costs based on usage. To simplify your decision, explore how AI in Your Pocket can help with everyday choices.
“Different lifestyles and medical needs require careful consideration when deciding between Medicare Advantage and Medigap.”
Medicare Enrollment Period 2025
2025 Medicare Enrollment Periods
Choose the right window for your case. Estimate total yearly cost, confirm provider access, and check drug coverage before you switch.
Initial Enrollment Period, IEP
When: Seven months around your 65th birthday, includes the three months before, your birthday month, and the three months after. If disabled, IEP occurs around the 25th month of disability benefits.
You can: Enroll in Part A and Part B, add a standalone Part D plan, or choose a Medicare Advantage plan that bundles A and B, usually Part D.
Medigap Open Enrollment
When: The six months that start the first month you have Part B and are 65 or older.
You can: Buy any Medigap plan sold in your state with no medical underwriting. After this window, acceptance can be restricted in many states.
Annual Election Period, AEP
When: October 15 to December 7.
You can: Join, switch, or drop Medicare Advantage and Part D plans. Changes take effect January 1.
Medicare Advantage Open Enrollment, MA OEP
When: January 1 to March 31.
You can: If you are already in a Medicare Advantage plan, switch to another MA plan once, or return to Original Medicare and add Part D. This window does not let people on Original Medicare newly join MA.
General Enrollment Period, GEP
When: January 1 to March 31.
You can: Enroll in Part A and/or Part B if you missed IEP. Coverage usually starts the month after enrollment. Late penalties may apply.
Special Enrollment Periods, SEPs
Common triggers: You move, you lose employer or union coverage, your plan changes its contract, you qualify for Extra Help or Medicaid.
Five Star SEP: Once per year you can switch to a five star Medicare Advantage or Part D plan from December 8 through November 30, subject to availability in your county.
What is the main difference between Medicare Part C and Medigap?
Medicare Advantage, Part C, replaces Original Medicare with a private plan that manages care and often bundles Part D and extras. Medigap supplements Original Medicare and helps pay deductibles, copays, and coinsurance.
Can I have both Medicare Part C and Medigap?
No. Medigap only works with Original Medicare. You cannot use Medigap with a Medicare Advantage plan.
Is Part D drug coverage included in Medigap?
No. Medigap does not include drug coverage. Pair Medigap with a standalone Part D plan to cover prescriptions.
What is the biggest disadvantage of a Medicare Advantage plan?
Lower premiums often come with tighter rules. Networks can be limited, referrals may be required, and out-of-network care usually costs more. Always confirm your doctors and drugs before enrolling.
HMO vs PPO for Medicare Advantage, which should I choose?
HMO can reduce costs if your doctors are in network and you are comfortable with referrals. PPO gives more flexibility at a higher typical cost. Match the structure to your usage and travel needs.
Medicare Advantage vs Medigap, how do I choose?
Estimate total yearly cost, include premiums, copays, drugs, and potential hospital stays. If you want predictable bills and nationwide access, consider Original Medicare plus Medigap and Part D. If you want extras like dental and are fine with managed networks, consider Medicare Advantage.
When can I enroll or change my plan?
IEP happens around your 65th birthday. AEP runs October 15 to December 7. MA OEP runs January 1 to March 31 for people already in MA. You may also qualify for Special Enrollment Periods after certain life events.
Conclusion
The best fit depends on how you use care and how much price predictability you want. Medicare Advantage can keep premiums low and add extras like dental or vision, although networks and prior authorization rules may limit flexibility. Medigap pairs with Original Medicare and Part D, it raises monthly cost and reduces surprise bills, while keeping nationwide access to any provider that accepts Medicare.
Run the numbers for your county. Compare yearly totals, confirm your doctors and drugs, and check star ratings.
If you value lower premiums and are comfortable staying in network, a Medicare Advantage plan can work. If you want broad access and stable out-of-pocket costs for frequent care, a Medigap plan with Part D is likely the safer choice.