Medigap Plan G vs. Plan N
Both can be strong Medigap options. The decision is whether the premium savings justify the additional cost-sharing and rules you accept with Plan N.
The practical difference
Plan G
After the Part B deductible, Plan G generally covers the standardized Medicare cost-sharing included in the plan, including Part B excess charges.
Plan N
Plan N can have a lower premium, but it leaves certain office and emergency-room copays and does not cover Part B excess charges.
Why the cheaper premium is not automatically cheaper overall
Plan N may save money in premiums, especially for someone who uses relatively little outpatient care. But the comparison should include expected copays, the possibility of excess charges, premium differences and how often you see providers.

Both still require Medicare Part B
Medigap does not replace Medicare. You keep Original Medicare and generally add a separate Part D plan for outpatient prescription coverage.
Do not ignore underwriting just because you can compare premiums today
If you are outside your Medigap Open Enrollment Period or a guaranteed-issue situation, changing Medigap policies later may require medical underwriting depending on state law and the circumstances.
Primary sources
This guide is based on current information from Medicare.gov and CMS. Rules can change, so verify time-sensitive details before acting.