Medicare Supplement

The Medigap window Hayward retirees only get once — and what changes after month six

For people turning 65 in Hayward, one of the most important Medicare rules has nothing to do with picking a plan in fall. It is a quiet six-month clock that starts the month your Medicare Part B coverage begins — and once it runs out, your Medigap choices may never look the same again.

Medicare SupplementHayward, CA

That six-month stretch is called the Medigap Open Enrollment Period. It is the one window when federal law guarantees you the right to buy any Medigap policy sold in California, at the best available price the insurer offers, no matter what your health history looks like. Miss it, and the rules shift in ways many people do not see coming.

What the Medigap Open Enrollment Period actually is

Medigap, also called Medicare Supplement Insurance, is a private policy that helps pay some of the out-of-pocket costs Original Medicare (Part A and Part B) leaves behind — things like coinsurance and hospital costs.

Under federal rules, when you are 65 or older and first enrolled in Part B, a six-month Medigap Open Enrollment Period begins automatically. During those six months, you have what is called a "guaranteed issue" right. That means:

• An insurer must sell you any Medigap policy it offers in your state.
• It cannot use your health history to charge you more.
• It cannot make you wait for coverage of most conditions (a limited pre-existing condition look-back can apply if you did not have prior creditable coverage).

This window opens once. It does not reset if you change your mind, move, or switch plans later.

Why this window matters in Hayward

Hayward is in Alameda County, where retirees have a wide mix of Medicare choices — Original Medicare, Medicare Advantage plans, and standalone Part D drug plans. Medigap is different from all of those. It works only with Original Medicare, and the shopping rules are set mostly by federal law with some state-level protections layered on top.

Because Alameda County offers many Medicare Advantage options, some people choose Advantage first and think about Medigap later. That is allowed — but it is exactly the situation where the six-month clock quietly closes in the background, and later switching to Original Medicare with a Medigap policy becomes harder.

What changes after the six months end

Once your Medigap Open Enrollment Period ends, insurers in most cases can use medical underwriting. That means when you apply, they can:

• Ask detailed health questions.
• Charge you a higher premium based on your health.
• Delay coverage of pre-existing conditions within allowed limits.
• Turn down your application entirely.

There are some limited situations — called guaranteed issue rights — where you get another protected chance to buy certain Medigap policies later, for example if a plan leaves your area or you lose other coverage. California also has a yearly "birthday rule" that lets existing Medigap policyholders switch to certain equal or lesser policies without underwriting for a set number of days around their birthday. These protections are narrower than the initial six-month window, so it is worth understanding them before you rely on them.

For the current rules, see the CMS Medicare Supplement Insurance pages at medicare.gov.

How this fits with the rest of Medicare in 2026

Medigap is only part of the picture. As you plan around your six-month window, keep the broader 2026 calendar and figures in mind:

• The Annual Enrollment Period runs October 15 – December 7 for changes to Part D and Medicare Advantage.
• The Medicare Advantage Open Enrollment Period runs January 1 – March 31.
• Part D has a $2,100 out-of-pocket cap in 2026, and the maximum Part D deductible is $615.
• The old coverage gap ("donut hole") is gone as of 2025; Part D now has three phases.
• The Medicare Prescription Payment Plan lets you spread drug costs across the year in monthly amounts.
• IRMAA surcharges for higher-income enrollees start above $109,000 in income for a single filer in 2026.

None of those numbers change your Medigap window — but they do affect the total cost picture you are comparing against.

A simple way to think about the decision

If you are approaching 65 in Hayward, it can help to walk through three questions before your Part B start date:

1. Do I want to be on Original Medicare with a Medigap policy, or on a Medicare Advantage plan? 2. If Medigap is even a possibility, do I want to lock in guaranteed issue rights during my six-month window? 3. Who can I talk to who does not sell insurance?

For that last one, California's State Health Insurance Assistance Program (SHIP) — known locally as HICAP — offers free, unbiased counseling. That, plus medicare.gov and 1-800-MEDICARE, will give you the official version of the rules before you make a call you cannot easily undo.