Medigap, or Medicare Supplement Insurance, is private coverage that fills gaps in Original Medicare (Part A and Part B) by reimbursing out-of-pocket costs. Plans are standardized by letter (A–N) in most states, with notable differences in a few states. Eligibility requires enrollment in Parts A and B, and the best buying window is the six‑month Medigap Open Enrollment Period, which guarantees coverage regardless of pre‑existing conditions. The most popular option among new enrollees is Plan G, while Plans C and F were discontinued for new beneficiaries in 2020; additional considerations include premiums, plan exclusions, and the interaction with Medicare Advantage. Looking ahead, understanding enrollment rules, plan benefits, and potential state variations is essential for choosing coverage and budgeting for future costs, including travel and prescription drug needs via Part D.
Dive Deeper:
Medigap is private insurance designed to supplement Original Medicare by covering specific out‑of‑pocket costs, with plans standardized largely by letter so the benefits are consistent within a given state for the same plan.
To be eligible, individuals must be enrolled in Medicare Parts A and B; in some states, under‑65 eligibility or special rules apply, making state residency a factor in availability.
The six‑month Medigap Open Enrollment Period begins the month you turn 65 and enroll in Part B, during which insurers must offer a policy without considering medical history and cannot quote higher premiums due to health issues.
Medigap plans cover items such as coinsurance, hospital costs, Part A and B cost shares, hospice and skilled nursing facility coinsurance, and sometimes the Part B deductible depending on the plan; foreign travel emergency care is included up to plan limits in many policies.
Medigap does not cover long‑term care, vision or dental, hearing aids, private‑duty nursing, or prescription drugs (which require a separate Part D plan); some plans also have provisions around Part B excess charges or deductibles.
Plan G has become the most popular option for new enrollees, covering nearly all benefits except the Part B deductible (which was $226 in 2025); Plan N is valued for lower premiums but imposes copayments for certain visits and does not cover Part B excess charges, illustrating tradeoffs between cost and coverage.