Medicare Supplement Insurance — commonly called Medigap — exists to fill the gaps that Original Medicare leaves behind: the 20% coinsurance on Part B services, the Part A hospital deductible ($1,676 in 2025), and a long list of cost-sharing that can add up fast for anyone with regular medical needs. Among the standardized Medigap plans sold in most states, Plan N has emerged as one of the more popular middle-ground options, offering substantial coverage at a meaningfully lower premium than the top-tier plans. But it comes with trade-offs that matter enormously depending on how often you see doctors and which physicians you use.
To understand Plan N, it helps to know where it sits in the Medigap lineup. The federal government standardizes Medigap plans — labeled A through N — so that a Plan N sold by Aetna covers the same core benefits as a Plan N sold by Mutual of Omaha or Blue Cross Blue Shield. What differs between insurers is the premium you pay, the company's financial stability, and customer service quality. In 2025, the most comprehensive widely available plan is Plan G, which covers virtually everything Original Medicare doesn't — except the Part B deductible ($257 in 2025). Plan N covers the same broad set of benefits as Plan G with two important exceptions: it requires cost-sharing at the point of care, and it does not cover Part B excess charges.
Here's what Plan N actually covers: the Part A hospital coinsurance and an additional 365 days of hospital coverage after Medicare benefits are exhausted; the Part A hospice care coinsurance or copayment; the Part A deductible ($1,676 in 2025); skilled nursing facility coinsurance; Part B coinsurance — but with copays, not full coverage; and foreign travel emergency care up to plan limits (typically 80% after a $250 deductible, up to a $50,000 lifetime maximum). What it does not cover is the Part B deductible and, critically, Part B excess charges.
The copay structure under Plan N is where most beneficiaries feel the difference day-to-day. When you visit a doctor's office, Plan N requires you to pay up to $20 per visit. When you go to an emergency room but are not admitted as an inpatient, you pay up to $50. These amounts are set by federal standardization rules and do not change based on which insurer sells you the plan. If you're admitted to the hospital through the ER, the $50 copay is waived. For someone who sees a primary care physician four times a year and a specialist twice, that's potentially $120 in annual copays — a modest amount that's often more than offset by the premium savings Plan N offers compared to Plan G.
The excess charge issue is more nuanced and deserves careful attention. Medicare sets an approved payment amount for every covered service. Doctors who accept Medicare assignment — meaning they agree to accept that approved amount as payment in full — cannot charge you more than your standard cost-sharing. But doctors who do not accept Medicare assignment can charge up to 15% above the Medicare-approved rate, and that extra amount is called an excess charge. Plan G covers those excess charges entirely. Plan N does not. If you see a non-participating physician who bills $200 for a service Medicare approves at $150, Medicare pays 80% of $150 ($120), Plan N pays the remaining $30 coinsurance, but you owe the $30 excess charge out of pocket. In practice, the majority of U.S. physicians — roughly 97% according to CMS data — do accept Medicare assignment, which means excess charges are relatively rare. However, certain specialties and geographic areas have higher concentrations of non-participating doctors, including some anesthesiologists, certain surgeons, and physicians in high-cost urban markets. If you live in a major metropolitan area or regularly see specialists, it's worth verifying your doctors' assignment status before choosing Plan N.
The premium savings with Plan N can be substantial. While premiums vary significantly by age, gender, tobacco use, and location, Plan N premiums are typically 20–30% lower than Plan G premiums for the same beneficiary profile. A 65-year-old woman in a mid-sized city might pay $130–$160 per month for Plan G and $100–$125 per month for Plan N. Over a year, that's a potential savings of $360–$420 — enough to cover several years' worth of office visit copays for a relatively healthy person. For beneficiaries who are generally healthy, see doctors infrequently, and whose physicians all accept Medicare assignment, Plan N can deliver meaningful value. For those with chronic conditions requiring frequent specialist visits or who use physicians known to bill excess charges, Plan G's higher premium may be the better financial protection.
Medigap enrollment timing is one of the most consequential decisions you'll make, and Plan N is no exception. Your guaranteed-issue window — the period during which insurers must sell you any Medigap plan at standard rates regardless of your health history — is the six-month period that begins the month you turn 65 and are enrolled in Medicare Part B. During this window, you cannot be denied coverage or charged higher premiums due to pre-existing conditions. Outside this window, most states allow insurers to use medical underwriting, meaning they can reject your application or charge you more based on your health. This is why choosing the right plan during your initial enrollment period matters so much: switching later may be difficult or expensive if your health has changed.
Thirteen states have enacted birthday rules that create an additional annual window for Medigap switching without medical underwriting. In California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, and Oregon, beneficiaries typically have a 30-day window around their birthday each year to switch to a Medigap plan with equal or lesser benefits without answering health questions. If you live in one of these states and are currently on Plan G but want to explore whether Plan N's lower premium makes sense, your birthday window may give you a path to make that switch. New York and Connecticut go further, offering guaranteed issue rights year-round for Medigap plans, making those states particularly flexible for beneficiaries who want to shop.
It's also important to understand that Medigap plans are not the same as Medicare Advantage plans, and the two cannot be combined. Medigap works alongside Original Medicare (Parts A and B) to cover cost-sharing. Medicare Advantage (Part C) replaces Original Medicare entirely with a private plan that typically includes network restrictions and its own cost-sharing structure. If you're currently in a Medicare Advantage plan and want to switch to Original Medicare plus a Medigap plan, you can do so during the Annual Enrollment Period (October 15–December 7) or the Medicare Advantage Open Enrollment Period (January 1–March 31), but you may face medical underwriting for the Medigap policy depending on your state.
When comparing Plan N quotes, look beyond the monthly premium. Ask each insurer how they set rates — community-rated plans charge everyone the same regardless of age, issue-age plans set your rate based on your age when you buy, and attained-age plans increase your premium as you get older. Attained-age plans often have the lowest initial premiums but can become significantly more expensive over time. Community-rated plans, available in some states, tend to offer the most predictable long-term costs. Also check the insurer's AM Best financial strength rating — you want a company rated A or better — and look at their history of rate increases in your state, which your state insurance commissioner's office can often provide.
For beneficiaries who want to verify their doctors' Medicare assignment status before committing to Plan N, Medicare's Physician Compare tool at medicare.gov allows you to search any provider and see whether they accept assignment. This is a practical step that takes about five minutes and can meaningfully inform your plan choice. If all your regular physicians accept assignment and you're in good health, Plan N's lower premium may represent the smarter financial choice. If even one or two of your key specialists are non-participating, the math shifts — and Plan G's excess charge coverage starts to look more valuable.
Finally, remember that Medigap plans do not include prescription drug coverage. Regardless of whether you choose Plan N, Plan G, or any other Medigap policy, you'll need to enroll in a separate Medicare Part D prescription drug plan to cover your medications. Part D plans are sold by private insurers, premiums and formularies vary by plan and location, and you can compare options at medicare.gov's Plan Finder tool. Failing to enroll in Part D when first eligible can result in a late enrollment penalty — 1% of the national base beneficiary premium for every month you went without creditable drug coverage — that stays with you permanently. Coordinating your Medigap and Part D choices together, rather than treating them as separate decisions, gives you the most complete picture of your total out-of-pocket exposure under Original Medicare.