A large part of Medicare’s usefulness stems from its ability to offset the cost of prescription drugs. If you are a California resident, Medicare’s Part D prescription drug plan is worth researching since it offers 25 separate plans from 13 different health insurance providers. To avail yourself of one of these plans, you’ll need to be enrolled in Original Medicare Part A or Part B prior to submitting your Part D prescription drug plan application. Applications can be found on the website of the health care company that provides the service. Quite often, the company will require you to fill out a traditional paper application as well, so be sure to speak with a representative directly to find out how to proceed.

You’ll want to enroll in the Part D plan of your choice as soon as possible, since the federal government does charge late enrollment fees. In some cases, you may even receive higher Part D premiums that rise each year that you use Medicare if you fail to enroll by the various deadlines.

Medicare Part D vs. Medicare Advantage

If you have a Medicare Advantage plan (also referred to as Medicare Part C), there are a few extra steps to take during your Part D research. The Part D prescription drug plan and Medicare Advantage are similar in some ways. Both plans are administered by third-party health insurance providers, and both plans act as supplements to Original Medicare. Medicare Advantage typically provides the same or better care as Original Medicare, however, whereas Part D only covers prescription drugs.

Some Advantage plans may in fact cover prescription drugs, but these Advantage plans will likely differ substantially from Part D plans in terms of price, availability in your region, and the type and amount of drugs covered. Due to all these variations, you should consider your options carefully when deciding on a Part D prescription drug plan versus a Medicare Advantage plan that also features drug coverage. In many cases, enrolling in a Part D plan will automatically cancel your Medicare Advantage plan. If this happens, you will revert back to Original Medicare Part A and Part B coverage along with your Part D plan, meaning that your choice of drug plans could impact the entirety of your Medicare coverage.

You should contact your prospective Part D plan administrator as well as the administrator of your Medicare Advantage plan prior to making any changes.

When to sign up

The federal government offers three options when it comes to signing up for Medicare Part D. The first of these, the Initial Enrollment Period, is the preferred one, since later enrollment periods may feature penalties or specialized requirements. The Initial Enrollment Period lasts for seven months, beginning three months prior to your initial Medicare eligibility date (which is based off of your birth month). The Part D initial enrollment period continues for four months past your initial eligibility date, which gives you a lengthy window in which to do your research before committing to a Part D plan.

If you fail to enroll during the seven month Initial Enrollment Period, you can try signing up during the Annual Election Period, which occurs each year from October 15th through December 7th.

If you miss both the Initial Enrollment Period and the Annual Election Period, your final option is a Special Election Period that happens at various times throughout the year. Medicare provides Special Election Periods to accommodate those with hardships and extenuating circumstances such as the loss of prior drug coverage or associated insurance. Contact Medicare directly at 1-800-633-4227 to inquire about Special Election Periods for Part D enrollment.

What are my choices?


The Medicare Part D services listed in the table above are provided in all of California’s counties. Your particular county may feature additional plans or services. Contact your local Medicare office for further information.

Source: CMS.gov

Plans are subject to change as contracts are finalized.

Includes contracts/plans as of April 22, 2016. The data does not reflect information for employer-sponsored plans, Part B-only plans, or plans not offering a Part D drug benefit.

by Lindsay Malzone, Lindsay Malzone is the Medicare expert for Medigap.com. She's been contributing to many well-known publications as an industry expert since 2017. Her passion is educating Medicare beneficiaries on all their supplemental Medicare options so they can make an informed decision on their healthcare coverage.