One of the largest out-of-pocket expenses for older adults in California is prescription drugs. Original Medicare, with its Parts A and B, does not cover most drugs you pick up at the pharmacy. That is what Medicare Part D is for. This guide explains how Part D works in California in 2026, how much it costs, how to choose the right plan for your specific medications, and how to avoid costly mistakes.
What Is Medicare Part D?
Medicare Part D is an optional prescription drug benefit offered through Medicare-approved private insurance companies. You can get it in two ways: as a standalone Prescription Drug Plan (PDP), which pairs with Original Medicare, or as part of a Medicare Advantage plan (MA-PD) that bundles medical and drug coverage in one plan.
If you have Original Medicare (Parts A and B) and do not have other creditable drug coverage, enrolling in a Part D plan is strongly recommended. It protects you from high pharmacy costs and prevents a permanent late enrollment penalty if you wait too long.
How Part D Works: The Formulary and Cost Tiers
Every Part D plan has a formulary, which is a list of covered drugs. Medications on the formulary are organized into cost tiers, and each tier has a different cost to you.
Typical formulary tiers
Tier 1 typically includes preferred generic drugs with the lowest copays, often $0 to $5. Tier 2 covers non-preferred generics. Tier 3 includes preferred brand-name drugs with moderate cost sharing. Tier 4 covers non-preferred brand-name drugs at higher costs. Tier 5 is reserved for specialty drugs, which are the most expensive and may require a percentage of the cost rather than a fixed copay.
If your doctor prescribes a drug that is not on your plan's formulary, you can request a formulary exception. Your doctor can submit documentation showing that this specific drug is medically necessary for your treatment.
The annual Part D deductible
In 2026, the maximum annual deductible for Part D plans is $590. Some plans have a $0 deductible, particularly for generic drugs. If your plan has a deductible, you pay the full cost of your medications at the start of the year until you reach that amount, before the plan starts covering its share.
The New $2,000 Out-of-Pocket Cap for 2026
This is one of the most significant improvements in Medicare's recent history. Starting in 2025, total out-of-pocket spending on Part D drugs is capped at $2,000 per year. Before this change, there was no clear ceiling, and some people with expensive specialty medications were spending tens of thousands of dollars annually.
Additionally, the Medicare Prescription Payment Plan lets you spread your drug costs into monthly payments throughout the year, rather than paying large sums upfront when deductibles reset in January.
Extra Help (Low Income Subsidy)
If your income and resources are limited, you may qualify for the Extra Help program, also known as the Low Income Subsidy (LIS). This federal program pays some or most of your Part D costs, including the monthly premium, the annual deductible, and your copays at the pharmacy.
Who can qualify for Extra Help?
In 2026, you may qualify if your annual income is approximately $22,590 or less for an individual, or $30,660 or less for a married couple. These limits adjust each year. Your resources, such as bank accounts and savings, generally must be $17,220 or less for an individual. Certain assets do not count, including your home, one car, and life insurance policies.
In California, if you qualify for Medi-Cal, you likely automatically qualify for Extra Help as well. If you receive Supplemental Security Income (SSI), you also qualify automatically.
With full Extra Help in 2026, many beneficiaries pay $0 in premiums, $0 in deductibles, and no more than $4.50 for generic drugs and $11.20 for brand-name drugs. If you think you may qualify, contact us and we will help you apply at no charge.
How to Choose the Best Part D Plan in California
With dozens of Part D plans available in California, choosing can feel overwhelming. These steps make it manageable.
Step 1: List your medications
Before comparing plans, write down every prescription drug you take, with the exact name (both generic and brand), the dose, and how often you take it. This list is the most important tool you have for finding the right plan.
Step 2: Use the Medicare plan comparison tool
The Medicare.gov website has a free plan finder where you enter your medications and zip code to see which plans cover them and at what cost. You can also enter your preferred pharmacy to see the specific copays you would pay there.
Step 3: Compare total cost, not just the premium
A plan with a low premium can cost you more if your specific drug is on a high tier or not covered. Always compare the estimated total annual cost, which includes the premium, deductible, and copays for all your medications combined.
Step 4: Verify the pharmacy network
Part D plans have preferred pharmacy networks where copays are lower. Make sure your regular pharmacy, whether it is a chain store or an independent neighborhood pharmacy, is in the plan's network. Many plans also offer lower mail-order prices for 90-day supplies of maintenance medications.
The Part D Late Enrollment Penalty
If you do not enroll in a Part D plan when you first become eligible for Medicare and go 63 or more consecutive days without creditable drug coverage, you may face a late enrollment penalty. This penalty equals 1% of the national base beneficiary premium for each full month without coverage, and it is added permanently to your monthly premium.
In 2026, the national base beneficiary premium is approximately $36.78. For example, if you waited 24 months to enroll in Part D without other creditable coverage, your penalty would be about $8.83 per month added permanently to your plan premium.
The simplest way to avoid this penalty is to enroll in a Part D plan during your 7-month Initial Enrollment Period, even if you do not currently take many medications. A basic plan with a low premium gives you protection and avoids any future penalty.
For a deeper look at all Medicare enrollment penalties, including Parts A and B, you can read the comprehensive guide on our partner site Medicare California.
Part D with Medicare Advantage vs. Standalone Plan
If you have a Medicare Advantage plan, it likely already includes drug coverage (MA-PD). In that case, you cannot and do not need a standalone Part D plan. Drug coverage through Medicare Advantage can be comprehensive and convenient, but you should always verify that all your specific medications are on the plan's formulary before enrolling.
If you have Original Medicare and a Medigap (Medicare Supplement) plan, you will need a standalone Part D plan for drug coverage. Medigap plans do not cover prescription drugs.
When You Can Change Your Part D Plan
The main window to change Part D plans is the Annual Enrollment Period (AEP), which runs from October 15 to December 7 each year. Changes take effect January 1 of the following year. During this period, it is worth comparing plans every year because formularies, premiums, and pharmacy networks change annually.
If you have a Medicare Advantage plan with drug coverage, you can also make changes during the Medicare Advantage Open Enrollment Period (MADP) from January 1 to March 31.
Frequently Asked Questions
What does Medicare Part D cover in California?
Part D covers prescription drugs included in the plan's formulary. Each plan has its own list of covered drugs organized into cost tiers. Generic drugs typically have the lowest copays; specialty medications may require a percentage of the cost.
How much does Medicare Part D cost in California in 2026?
Premiums range from under $10 to over $100 per month depending on the plan. The maximum annual deductible is $590. In 2026, your total out-of-pocket cap for covered drugs is $2,000 per year, which is a significant protection for people who take expensive medications.
What happens if I do not enroll in Part D when I am first eligible?
If you go 63 or more consecutive days without creditable drug coverage, you face a permanent penalty of 1% of the national base premium for each month without coverage. This is added to your monthly premium for as long as you have Part D.
Can I change my Part D plan in California?
Yes. During the AEP (October 15 to December 7) you can change your plan, with the new plan effective January 1. It is recommended to compare plans each year since formularies and costs change annually.
Need Help Choosing Your Drug Plan?
Our licensed California agents are bilingual and can help you compare Part D plans based on your specific medications. The consultation is completely free and there is no obligation.
Talk to an Agent TodayYour Medications, Your Plan
Medicare Part D can seem complex, but the core idea is straightforward: know your medications, compare plans based on total cost rather than premium alone, and do not delay enrollment. With the new $2,000 out-of-pocket cap and the Extra Help program for people with limited incomes, there are more protections than ever for Californians who rely on prescription drugs.
If you have questions about choosing your Part D plan or want to find out if you qualify for Extra Help, contact us today for a free review.
Share this with someone you love. If you know someone who recently enrolled in Medicare or is turning 65 soon, this information about drug coverage could save them money and help them avoid unnecessary penalties.