San Mateo, California residents can choose from Original Medicare, Medicare Advantage, Medicare Supplement (Medigap), and Part D prescription drug plans, with availability set at the county level for Advantage and Part D. San Mateo has its own Social Security field office located in the city. Independent, no-pressure plan comparisons are available free by phone or video.
Key Enrollment Dates: –
Initial Enrollment Period: 7-month window around your 65th birthday
Annual Enrollment Period: October 15 – December 7
General Enrollment Period: January 1 – March 31
Looking for Medicare Supplement coverage in San Mateo? Whether you’re turning 65 soon or already enrolled in Original Medicare, choosing the right Medigap plan can feel overwhelming. A Medicare agent serving San Mateo can simplify the process so you can protect your retirement savings, avoid high out-of-pocket costs, and keep the doctors you trust.
MedicareVideoGuide.com provides independent Medicare enrollment guidance for San Mateo, California residents in the 94401, 94402 and 94403 ZIP codes, entirely online by phone or video. As a San Mateo resident in San Mateo County, the specific Medicare Advantage and Part D plans available to you are set at the county level by CMS.
Video Caption: Medicare enrollment overview
Video Summary: This video walks through how Original Medicare, Medicare Advantage, Medigap, and Part D fit together, and what typically determines which combination makes the most sense depending on your health needs and budget.
Delaying Medicare while working past 65 in San Mateo is a practical choice for many people — but it comes with rules that are easy to misunderstand. When you have employer insurance through your own job or a spouse’s, you may qualify for a Special Enrollment Period that lets you sign up for Medicare later without a late penalty. However, the size of your employer, how your plan coordinates with Medicare, and your specific retirement timeline all affect when and how you should make the switch. A licensed Medicare agent serving San Mateo can review your current employer coverage, help you understand exactly when to enroll, and make sure switching to Medicare goes smoothly without gaps, penalties, or unexpected costs along the way.
Video Caption: Working Past 65 and Medicare
Video Summary: This video covers how Medicare coordinates with employer coverage when you’re still working past 65 — which parts you can safely delay, how group health plan size changes the rules, and the enrollment window that opens once you eventually leave that job.
One of the most important questions for many people on Medicare is whether they can keep seeing their current doctors and specialists. With Original Medicare and a Medicare Supplement plan, you can generally see any doctor or hospital in the United States that accepts Medicare. Medicare Advantage plans work differently because they often use provider networks, so it is important to check whether your doctors, hospitals, and specialists in or near San Mateo are included before enrolling.
Source: KFF
Video Caption: Keeping your doctors on Medicare
Video Summary: This video explains why network access is one of the biggest practical differences between Medigap and Medicare Advantage, especially if you have doctors you don’t want to give up.
Medicare Advantage plans use narrower networks tied to specific hospital systems — KFF’s national analysis found enrollees have access to roughly half the physicians available to someone on Original Medicare in the same area.
Source: KFF
Rising Medicare Supplement premiums catch a lot of San Mateo residents off guard, especially if they’ve stuck with the same carrier for years without comparing options. Because Medigap coverage is standardized, switching carriers for a lower rate doesn’t mean giving up any benefits — Plan G is Plan G no matter who sells it. A Medicare agent serving San Mateo can pull current rates from multiple carriers so you can see whether you’re overpaying for identical coverage.
Video Caption: Why Medigap premiums rise
Video Summary: This video breaks down why Medigap premiums for the exact same plan can rise at very different rates from one carrier to the next, and what that means for shopping around later without medical underwriting getting in the way.
The Social Security field office serving San Mateo is located within the city.
This is the office where you can apply for Medicare, apply for Social Security retirement benefits, or request a replacement Social Security card in person.
San Mateo Social Security Office 800 South Claremont Street, Suite 101, San Mateo, CA 94402 📍 Get Directions on Google Maps
Phone: (866) 726-8193 Fax: (833) 950-2108 Hours: Monday–Friday, 9:00 AM–4:00 PM (closed weekends and federal holidays — call ahead to confirm, as hours are subject to change)
This office also serves nearby Burlingame, Foster City, and Hillsborough.
Services available at this office: –
✅ Apply for Social Security retirement benefits
✅ Enroll in Medicare Part A and Part B
✅ Apply for Social Security Disability Insurance (SSDI)
✅ Apply for Supplemental Security Income (SSI)
✅ Request a new or replacement Social Security card
✅ Update direct deposit information
✅ Apply for spousal or survivor benefits
✅ Request a benefit verification letter
An appointment is strongly recommended over walking in. Many of these tasks can also be completed online at ssa.gov without an office visit.
Also asked as: “what if I forgot to sign up for Medicare on time”
Missing your Medicare enrollment deadline can result in a permanent late enrollment penalty added to your Part B or Part D premium. It can also create a gap in coverage until the next enrollment period opens.
Also asked as: “can I get Medicare early if I stop working”
Medicare eligibility begins at age 65 for most people, regardless of when you retire. Exceptions exist for certain disabilities or specific medical conditions, such as End-Stage Renal Disease, which can qualify you for Medicare before age 65.
Also asked as: “can I sign up for Medicare outside the normal enrollment window”
A Medicare Special Enrollment Period is a window outside the standard enrollment periods that lets you sign up for or change Medicare coverage following a qualifying life event. Common qualifying events include losing employer health coverage or moving to a new service area.
Also asked as: “should I get Medicare Advantage or a Medicare supplement”
Medicare Advantage replaces Original Medicare and typically uses a provider network, often bundling in extra benefits like dental or vision. Medigap works alongside Original Medicare to help pay its deductibles and coinsurance, and it lets you see any provider nationwide who accepts Original Medicare.
Also asked as: “can I combine Medicare Advantage with a supplement plan”
No — Medigap is designed to work only with Original Medicare. If you’re enrolled in a Medicare Advantage plan, a Medigap policy cannot be used alongside it.
Also asked as: “why is my Medicare premium higher than everyone else’s”
IRMAA stands for Income-Related Monthly Adjustment Amount. It’s an additional charge added to your Part B and Part D premiums if your reported income is above a certain threshold, based on your tax return from two years prior.
CMS sets Medicare Advantage and Part D plan service areas at the county level. Insurance companies decide which counties to offer a plan in based on their own network and cost calculations, which means two people a few miles apart in different counties can have a genuinely different set of plans to choose from — even within the same metro area. Your independent Medicare agent can pull up the specific plans available in your county so you’re comparing your actual options.
Medicare decisions deserve careful planning, whether you’re turning 65, retiring soon, moving to San Mateo, or leaving employer coverage.
Reach out today for a free, no-pressure Medicare plan comparison based on your ZIP code (94401, 94402 or 94403), preferred doctors, and prescriptions — every consultation is handled by phone or video, on your schedule.
Rodney Powell is an independent Medicare broker licensed in Texas and 36+ additional states nationwide, with carrier appointments including Physicians Mutual, United American, UnitedHealthcare (AARP), Humana, Aetna, Healthspring, Devoted, and KelseyCare. Rodney partners with HR and benefits professionals, CPAs, financial planners, real estate professionals, elder law attorneys, and senior group leaders to help people navigate Medicare enrollment with confidence. Learn more about Rodney →
Last Reviewed: May 31, 2026
By submitting your information, you agree that a licensed insurance agent may contact you by phone or email to answer your questions or provide additional information about Medicare Advantage or Prescription Drug Plans or Medicare Supplement Insurance plans. This is an advertisement for insurance.
Privacy Policy
We do not offer every plan available in your area. Currently we represent six organizations offering thirty products in your area. Please contact Medicare.gov, 1-800-MEDICARE, or your local State Health Insurance Program (SHIP) to get information on all of your options.
Not connected with or endorsed by the United States government or the federal Medicare program.
HEARTWISE, a Senior Health Services affiliate
Copyright © 2026 HEARTWISE, LLC | Privacy Policy