Plan N may be a good choice for you for two reasons: 1) it has a lower monthly premium, and 2) it comes with predictable out-of-pocket expenses.
You know what the annual deductible is for Part B ($203 in 2021), and for Part B excess charges, you’ll pay up to an additional 15% of the cost of the service. However, most providers don’t charge excess charges, so you usually don’t have to worry about them anyway.
With that in mind, Plan N is not the most comprehensive Medicare Supplement plan, so it’s wise to compare rates and review details of all plans (including F and G) to find the policy that best fits your needs.