Blog / Part D

How do I sign up for Part D for the first time?

You need Part A or Part B first. Then pick a plan on the Medicare Plan Finder using your drug list, and enroll online, by phone with the plan, or through an agent.

Updated September 3, 2026 · 3 min read · by Gerino Alejos

You sign up for Part D by picking a drug plan and enrolling in it, online at Medicare.gov, by phone with the plan, or through a licensed agent. You need Part A, the hospital part of Medicare, or Part B, the doctor visit part, first. Enrolling takes about fifteen minutes and choosing takes about thirty, so do the choosing first.

What you need first: Part A or Part B

• Part A or Part B. You need at least one.
• Your Medicare number and start dates, printed on your Medicare card.
• A full list of your medications with the dose of each one.
• The name of the pharmacy you use.

If you do not have your Medicare card yet, see how to enroll in Medicare first.

Choose the plan before you enroll

1. Go to the Plan Finder at Medicare.gov and enter your ZIP code.
2. Enter every medication with the exact dose.
3. Add your pharmacy, and add mail order.
4. Sort by total estimated yearly cost, not by the premium, the monthly bill for the plan.
5. Check the top few plans for prior authorization, step therapy and quantity limits, the rules that can hold up a drug at the counter.

Three ways to enroll

• Through the Plan Finder at Medicare.gov, straight into the plan you chose
• Directly with the plan, by phone or on its website
• Through a licensed agent

The premium is the same all three ways, because plan premiums are filed with CMS, the federal agency that runs Medicare. An agent adds a comparison across companies and someone to call when a drug gets denied.

When you can enroll

• Your Initial Enrollment Period, the seven months around your 65th birthday
• Annual Enrollment, October 15 to December 7, with coverage starting January 1
• Within two months of losing creditable employer drug coverage, coverage at least as good as Part D
• A special enrollment period, an extra window after a move, a change in Medicaid or Extra Help, or your plan leaving the area

See all the Part D enrollment windows.

After you enroll

1. Keep the confirmation, along with the plan name and the date.
2. Your plan card arrives before your start date. Take it to the pharmacy.
3. If you had another drug plan, it ends on its own when the new one starts.
4. Fill a prescription early in the first month to confirm everything works.

Check Extra Help first

Extra Help is a Medicare program that lowers drug costs for people with limited income. If that is you, apply before you enroll. It cuts premiums, deductibles, the amount you pay before the plan pays, and copays, the set amount you pay per fill. It also waives the late enrollment penalty and lets you switch plans more often during the year.

Many people in South Texas who qualify never apply. See how Extra Help works.

Start with your drug list and the Plan Finder, then enroll in the plan with the lowest total cost. If you would rather go through the list together, call our McAllen office or send us your ZIP code through the form on this page.

Gerino Alejos

Licensed insurance agent · License 3128710 · NPN 18243381

Owner of McAllen Insurance Group, an independent agency on North 10th Street in McAllen. Works with clients across Hidalgo, Cameron and Starr counties on Medicare, Marketplace health, life and auto coverage. Se habla español.