Medicare Part D

Before you switch drug coverage in El Cajon: how the two paths actually work

EL CAJON, Calif. — If you take even one regular prescription, how you get your Medicare drug coverage matters. In El Cajon, that usually comes down to two paths: a stand-alone Part D plan added to Original Medicare, or a Medicare Advantage plan that folds drug coverage inside. They look similar on paper — both cover prescriptions — but the way they're built, and what happens when you move between them, is quite different.

Here's a plain-English guide to how the two structures compare, and what to think about before switching.

Two different structures, not just two different prices

With Original Medicare (Parts A and B), the federal government covers your hospital and medical care directly. Prescriptions aren't included, so most people add a stand-alone Part D plan from a private insurer. Many also add a Medigap (Medicare Supplement) policy to help with the out-of-pocket costs Original Medicare leaves behind.

With a Medicare Advantage plan (Part C), a private insurer delivers your Part A and Part B benefits, and most plans also include Part D drug coverage in the same package. That's often called an "MA-PD" plan. You typically use the plan's network of doctors and pharmacies, and one card handles most of it.

So the core difference isn't just cost — it's structure. One path keeps drug coverage separate. The other bundles it in.

What stays the same

Whichever path you're on, the Part D rules set by Medicare still apply:

• The out-of-pocket cap on covered drugs is $2,100 in 2026 and $2,400 in 2027. After you hit it, you pay nothing for the rest of the year on covered prescriptions.
• The maximum Part D deductible is $615 in 2026 and $700 in 2027 (plans may charge less).
• The coverage gap, or "donut hole," is gone as of 2025. Part D now has three phases instead of four.
• The Medicare Prescription Payment Plan lets you spread your drug costs across the year in monthly amounts, at no extra charge, on either path.
• IRMAA (a higher-income surcharge) can apply to Part D premiums starting above $109,000 in income for a single filer in 2026.

These rules don't change based on whether your Part D comes stand-alone or built into an Advantage plan.

What changes if you move between the two

El Cajon is in San Diego County, where residents can choose from a range of stand-alone Part D and Medicare Advantage plans offered by private insurers. Moving between the two paths can mean more than just a new drug list.

• From Original Medicare + stand-alone Part D → Medicare Advantage: You'll usually get your medical and drug coverage from the same plan. You'll follow that plan's network and rules. If you had a Medigap policy, you generally won't need it while on Advantage — but re-buying Medigap later isn't always guaranteed, depending on your health and California's rules.
• From Medicare Advantage → Original Medicare: Original Medicare doesn't include drug coverage, so you'll likely want to add a stand-alone Part D plan to avoid a late-enrollment penalty. You may also want to look at Medigap, though medical underwriting can apply outside certain windows.

Each drug plan has its own formulary (list of covered drugs), preferred pharmacies, and prior authorization rules. When you switch, check that your specific prescriptions are still covered.

When you can make changes

Two main windows matter:

• Annual Enrollment Period: Oct. 15 – Dec. 7. You can join, switch, or drop a Part D or Medicare Advantage plan. Changes take effect Jan. 1.
• Medicare Advantage Open Enrollment Period: Jan. 1 – March 31. If you're already in an Advantage plan, you can switch to another Advantage plan or return to Original Medicare (and add a stand-alone Part D plan).

Special Enrollment Periods can also apply after certain life events, like moving or losing other coverage.

How to decide which path fits you

There's no single right answer. A few honest questions can help:

• Do you want one plan or separate pieces? Advantage bundles medical and drug coverage. Original Medicare + Part D keeps them apart, which some people prefer for flexibility.
• How important is provider choice? Original Medicare is accepted by most doctors nationwide. Advantage plans generally use networks.
• Are you thinking about Medigap? It only works with Original Medicare, and buying it later can involve health questions.
• What drugs do you take? Check each plan's formulary and pharmacy network before you decide.

Your local State Health Insurance Assistance Program (SHIP) — called HICAP in California — offers free, unbiased counseling and can walk through your specific situation.