5 Medicare mistakes I see San Antonio seniors make every year.

I've been doing this for 20+ years. The same five mistakes show up in San Antonio every single year, often in the exact same order. Here they are, ranked by how much they actually cost people.

Mistake #1: Picking a plan based on premium alone

The most expensive mistake, by a wide margin. Someone sees a $0 monthly premium Medicare Advantage plan and assumes it's the best deal. Then they discover three months in that their cardiologist isn't in-network, their pharmacy isn't preferred, or their cancer drug is on Tier 4 with 33% coinsurance.

The "free" plan ends up costing them $2,000+ more than the $35/month plan that actually fit their situation. Real numbers, real San Antonio clients.

How to avoid it

Compare the annual total cost, not the monthly premium. That means: premium × 12 + estimated copays + uncovered drugs + uncovered doctor visits. A good agent runs your real prescriptions through the plan's formulary and checks your doctors against the network before you enroll. If they don't do this, find a different agent.

Mistake #2: Waiting until the birthday to deal with Medicare

The Initial Enrollment Period is a 7-month window — 3 months before, the birth month, and 3 months after. People assume they should sign up on their birthday. Wrong.

If you enroll before your birth month, coverage starts the first of your birth month. If you enroll during or after, coverage starts later. People who wait until their birthday often have a coverage gap of 1–3 months — exactly when they're transitioning off employer coverage, exactly when they don't want to be uninsured.

How to avoid it

Start educating yourself 5–6 months before your 65th birthday. Talk to an agent 3 months before. Enroll 2 months before. Coverage starts the moment you turn 65 with no gap and no scramble.

Mistake #3: Skipping Part D because you "don't take medications"

If you don't take prescriptions at 65, congratulations — you're lucky. But the average American 65+ takes 4 prescriptions, and that number goes up every year after retirement. Most people who say they "don't take medications" at 65 are taking 2–3 by age 70.

Here's the problem: if you go 63+ days without "creditable" prescription drug coverage after becoming Medicare-eligible, you pay a permanent late enrollment penalty on Part D for the rest of your life. The penalty compounds at roughly 1% of the national base premium per month you went without coverage. Skip Part D for 5 years and you're looking at a 60%+ surcharge on whatever Part D plan you eventually pick.

How to avoid it

Sign up for the cheapest Part D plan available during your Initial Enrollment Period — even if you take zero medications. Some plans are $5/month. The $60/year buys you permanent protection from late enrollment penalties and ensures you have coverage when you eventually need it.

Mistake #4: Picking Medicare Advantage at 65 without understanding the Medigap door closes

This one breaks my heart because it's irreversible for many people.

When you first enroll in Part B at 65, you get a 6-month Medigap Open Enrollment Period. During this window, Medicare Supplement carriers in Texas must sell you any plan they offer, at the standard rate, with no medical underwriting. No health questions, no denials, no waiting periods.

Once that window closes, Texas carriers can use medical underwriting. They can decline you, charge you significantly more, or apply waiting periods based on your health history.

Many people pick Medicare Advantage at 65 because the $0 premium is attractive. Then their health changes 5 years later — they get diabetes, develop heart problems, get diagnosed with cancer — and they try to switch to Medigap because their Advantage plan's network keeps shifting around. They can't qualify. They're stuck.

How to avoid it

If there's any chance you might want Medigap eventually, start with Medigap during your open enrollment window. You can always switch from Medigap to Medicare Advantage later — Advantage has guaranteed issue every year during AEP. The reverse is not true. This is a one-way door for many people, and most agents don't explain it clearly.

Mistake #5: Going with the first agent who called you

If you're approaching 65 in San Antonio, your phone is about to start ringing. A lot. Most cold callers are working from purchased lead lists. They're paid only if they enroll you. Their pitch is engineered to close the sale on the call, not to find the right plan for you.

Common red flags:

• "This plan is only available for the next 48 hours" (false — Medicare plans don't work like timeshares)
• "I work for Medicare" (false — there's no such thing; agents work for carriers or independently)
• "You need to switch right now or you'll lose your benefits" (false — switching urgency is manufactured)
• Sales pitch starts before any questions about your doctors, prescriptions, or budget
• Carrier name dropped without comparison — "this Humana plan is amazing" instead of "let me compare across carriers"

How to avoid it

Find an agent through referral (ask a friend or family member who's happy with theirs) or through local search (Google "independent Medicare agent [your city]"). Avoid call centers. Avoid online lead-gen funnels that promise to "compare 50 plans in 60 seconds" — that's bait, and the agent who calls you is buying your information from the lead seller.

A good agent asks more questions than they answer for the first 10 minutes of the call. They want to understand your situation before making any recommendation.

The honorable mentions (mistakes 6, 7, 8)

• Not reviewing your plan every AEP. Plans change every year. Your perfect plan in 2025 may not be your perfect plan in 2026. Annual review is non-negotiable.
• Trusting the Medicare.gov plan finder without an agent. The tool is good. It's not perfect. Things it misses: which pharmacies are "preferred" vs. "standard" in your area, drug tier changes for the upcoming year, network differences between similar-looking plans.
• Skipping the dental/vision/hearing conversation. Original Medicare doesn't cover routine dental, eye exams, or hearing aids. Plan for this gap. Either pick an Advantage plan that includes these or budget for standalone coverage.

The pattern in all five

Look at what these mistakes have in common: they all come from not having someone in your corner who's actually paid to help, not paid to sell. Independent agents are paid by the carrier when you enroll — the same commission whether you go through them or directly. Using an independent agent literally costs you nothing and prevents almost all of these mistakes.

If you're approaching 65 in San Antonio or the Texas Hill Country, find one. Call me, call someone else — but find someone who'll spend 30 minutes understanding your situation before recommending anything.