California Medicare Supplement Calculator 2026

California Medigap Plans Explained

Medicare Supplement insurance — commonly called Medigap — fills the coverage gaps left by Original Medicare (Parts A and B). In California, private insurers sell standardized Medigap plans labeled A through N. The two most popular plans in 2026 are Plan G and Plan N.

Plan G is the most comprehensive option available to beneficiaries who enrolled in Medicare on or after January 1, 2020. It covers the Part A deductible ($1,676 in 2026), skilled nursing coinsurance, Part B excess charges, and foreign travel emergency care. The only gap is the Part B deductible ($257 in 2026). In California, the average Plan G premium for a 65-year-old is approximately $165/month.

Plan N offers lower premiums — averaging about $128/month for age 65 in California — in exchange for modest copays: up to $20 for office visits and $50 for emergency room visits (waived if admitted). Plan N does not cover Part B excess charges, which doctors who do not accept Medicare assignment may charge.

Plan F covers everything Plan G covers plus the Part B deductible. It is only available to those who became eligible for Medicare before January 1, 2020. If you are eligible, Plan F premiums in California average around $214/month at age 65.

All Medigap plans in California are standardized by the federal government — a Plan G from one insurer offers identical benefits to a Plan G from any other. The difference between insurers is price, financial strength, and customer service. Last updated: May 2026.

California Issue-age Rate System

Insurance companies in California use the Issue-age pricing method to set Medigap premiums. Issue-age rating locks your premium at the rate for your age when you first enroll. Premiums still rise with inflation but not because you age. California has a birthday rule allowing plan switches each year.

Under Issue-age rating in California, premiums are also influenced by gender (male enrollees typically pay 5–8% more), tobacco use (20% surcharge is common), and household discounts (5% off when multiple people in the household have coverage from the same insurer).

Because California uses Issue-age pricing, the best strategy for most beneficiaries is to enroll during your Medigap Open Enrollment Period — the six-month window starting the month you turn 65 and enroll in Medicare Part B. During this window, insurers cannot deny coverage or charge higher premiums based on your health history. Once this window closes, California insurers may use medical underwriting outside of specific guaranteed-issue situations.

Comparing quotes from multiple insurers in California is essential. Premiums for the same plan can vary by 30–50% between carriers, even for identical coverage. Use this calculator as a starting estimate, then get personalized quotes from a licensed California Medicare broker.

When to Buy or Switch Medigap in California

The single best time to enroll in a Medigap plan in California is during your Initial Enrollment Period: the six-month window when you first turn 65 and enroll in Medicare Part B. Federal law guarantees you can buy any Medigap plan sold in California at this time, with no medical underwriting and no risk of denial.

After your Open Enrollment Period ends, switching Medigap plans in California becomes more complicated. In California, the birthday rule gives you a 30-day window each year (around your birthday) to switch to an equal or lesser Medigap plan without health questions.

There are also federal Guaranteed Issue situations — such as losing employer coverage, moving out of your Medicare Advantage plan's service area, or your plan going bankrupt — that allow you to buy a Medigap policy without underwriting in California.

Before switching plans, compare the premium savings against potential out-of-pocket exposure. A lower-premium Plan N saves money month-to-month but may cost more if you need frequent specialist visits. Run the numbers using this calculator, and consult a licensed California Medicare advisor for personalized guidance. Based on CMS 2026 data for California (CA).