Medicare Supplement

Before you compare Medigap in Ontario, check these 2026 resets

ONTARIO, Calif. — If you have a Medigap policy in San Bernardino County, or you are shopping for one this fall, a few things move on the calendar every year. The plan letters that new enrollees can buy are set by federal rules, the Part B deductible that Plans G and N are built around resets on January 1, and California insurers file their rate adjustments with the state. Here is a plain-English look at what is changing for 2026 and how Ontario readers can check the details that apply to them.

Medicare SupplementOntario, CA

What Medigap is, in one paragraph

Medigap — also called Medicare Supplement Insurance — is a private policy that helps pay some of the out-of-pocket costs Original Medicare leaves behind, like coinsurance and copays. Policies are "standardized," meaning a Plan G from one company covers the same core benefits as a Plan G from another. What can differ is the price, the customer service, and whether the company is even selling that letter in California.

Plan-letter eligibility: who can buy what

Federal rules split Medigap shoppers into two groups based on when they first became eligible for Medicare.

• If you became eligible on or after January 1, 2020, you can buy Plans A, B, D, G, G-HD, K, L, M, or N.
• If you became eligible before January 1, 2020, you can still buy — or keep — Plans C and F, including the high-deductible version of F where offered.

That rule has not changed for 2026. It matters in Ontario because if you are aging into Medicare this year, Plans C and F are simply not on your menu, no matter which company you call.

The Part B deductible reset that Plans G and N are built around

Plans G and N are the two letters most new enrollees compare, and both are designed to pick up costs after you meet the Part B deductible each year. That deductible resets every January 1. The 2026 figure is set by CMS and posted on medicare.gov — check it there before you sign anything, because it is the number that determines what you pay out of pocket before your Medigap policy starts filling gaps.

High-deductible Plan G (G-HD) works differently: you pay a separate, higher plan deductible before the policy pays. Several California carriers offer G-HD, and they are noted in the table below.

Rate-adjustment season in California

Medigap premiums are not fixed by Medicare. In California, insurers file proposed rate changes with the California Department of Insurance (CDI), and those filings are public. If your renewal letter arrives and the number surprises you, you have two useful moves:

1. Look up your carrier's filing on the CDI website to see the rate change it filed for your plan letter and rating class. 2. Compare quotes from other California-licensed Medigap carriers for the same plan letter — because the benefits are standardized, you are comparing price and service, not coverage.

California also has its own "birthday rule," which lets Medigap enrollees switch to an equal or lesser plan from any carrier during a set window around their birthday without new medical underwriting. That is a state protection worth knowing about at rate-adjustment time; your local SHIP counselor (HICAP in California) can walk you through it.

Which insurers sell Medigap in California

Fifteen companies are listed as selling Medigap in California, and the plan letters they offer vary. The table on this page shows every insurer and every letter each one sells — from AARP - UnitedHealthcare Insurance Company at the top of the alphabet through USAA Life Insurance Company at the bottom. If you are specifically shopping a high-deductible Plan G, for example, the table lets you narrow the list to the carriers that actually file it in the state.

Because Medigap is regulated at the state level, "entering or leaving" news shows up in state filings, not in the federal Medicare Advantage announcements you may see each fall. The CDI filings are the place to confirm which companies are actively writing new business in California in 2026.

What Ontario readers should do before January 1

• Confirm the 2026 Part B deductible on medicare.gov so you know the number Plans G and N are built around.
• Read any renewal letter carefully and compare it to the carrier's rate filing at the California Department of Insurance.
• If you want a second opinion, call California's HICAP program (the state's SHIP) for free, unbiased counseling.
• For Medicare questions generally, call 1-800-MEDICARE (1-800-633-4227), TTY 1-877-486-2048.