Key Takeaways

  • Most Medicare Part D prescription drug plans and Medicare Advantage plans that include drug coverage generally include omeprazole in their formulary (drug list), though coverage can vary.
  • While Medicare Part D typically doesn’t cover over-the-counter omeprazole, some Medicare Advantage plans may offer an allowance for over-the-counter drugs, enabling you to purchase it with your plan.
  • The cost of omeprazole with Medicare depends on factors such as the plan’s deductible and the drug’s tier within the plan’s formulary, with generic versions being significantly cheaper than the brand-name version, Prilosec.

Omeprazole (Prilosec) treats digestive issues like stomach and duodenal ulcers, GERD, and esophagitis. It reduces stomach acid and can be combined with antibiotics to treat H. pylori infections.

You can purchase omeprazole over the counter or with a prescription. Anyone who wants to get this drug over the counter will have to pay for it out of pocket in most cases.

Read on to learn about using your Medicare Part D prescription plan or Medicare Advantage (Part C) plan with drug coverage to purchase prescription omeprazole and what you may expect to pay out of pocket in this case.

Medicare Part D plans generally cover take-home prescription drugs. Your specific plan’s coverage of the generic omeprazole or the brand Prilosec depends on whether it includes this drug in its formulary. That said, research suggests that many Part D plans do cover the prescribed version of this drug.

It’s important to understand, however, that while you cannot use your Part D plan to buy over-the-counter omeprazole, some insurers may ask you to purchase it over the counter to see whether the lower dose is sufficiently effective before they grant coverage for the prescribed version. This prior authorization process is called step therapy.

If you’re enrolled in a Medicare Advantage plan that includes prescription drug coverage instead of a stand-alone Part D plan, whether your plan covers this drug equally depends on the plan. That said, some MAPD plans may offer an allowance for over-the-counter drugs as part of their benefits, which means that you’d be able to purchase the drug over the counter with your plan.

Thirty capsules of 40-mg generic omeprazole cost between $10 and $48, depending on the pharmacy that dispenses them. The delayed-release version costs a similar amount.

In comparison, the brand drug Prilosec costs between $448 and $476 when purchased with a prescription, making the out-of-pocket costs significantly higher than the over-the-counter Prilosec or the generic.

If you have a prescription for Prilosec or one of the generic versions that aren’t available over the counter, how much you will end up paying after your Medicare plan kicks in depends on the tier in which the drug is classified in your plan’s formulary. Generally, the higher the tier, the more you’ll pay.

In addition, both Medicare Advantage and Part D plans generally require you to meet a deductible and pay a monthly premium, which varies by plan. The national base beneficiary premium for Part D is $36.78 in 2025 ($38.99 in 2026), while the average monthly premium for Medicare Advantage plans is around $17.00.

In addition, to be enrolled in a Medicare Advantage plan, you still have to pay the Part B premium. That said, some Medicare Advantage plans may cover some or all of your Part B premium.

Private insurers manage both Medicare Advantage and Part D plans. Some insurers may exclude omeprazole because it’s available over the counter.

That said, over-the-counter omeprazole only comes in a 20-mg dose, whereas with a prescription, you can get a 10-mg, 20-mg, and a 40-mg dose, depending on your needs.

Medicare Part B doesn’t cover omeprazole. Part B only covers medications you cannot take yourself, such as IV drugs or those you need to take with the help of a healthcare professional in a clinic or hospital setting.

Omeprazole may cause mild side effects such as:

  • headache
  • stomach pain
  • nausea
  • vomiting
  • diarrhea
  • gas
  • constipation
  • cold
  • cough
  • dizziness
  • rash
  • weakness
  • back pain
  • mild allergic reactions

These usually resolve in a few days or weeks.

Serious side effects are rare but include:

  • kidney issues
  • severe C. diff diarrhea
  • low magnesium
  • vitamin B12 deficiency
  • higher bone fracture risk
  • severe skin reactions
  • lupus
  • severe allergic reaction



Medicare Part D doesn’t cover:

  • drugs to manage appetite or weight
  • fertility drugs
  • drugs needed for cosmetic purposes or hair growth.
  • cough and cold drugs
  • prescription vitamins and minerals, except prenatal vitamins and fluoride.
  • over-the-counter drugs
  • drugs needing specific manufacturer tests or monitoring.
  • erectile dysfunction drugs, unless needed for other Food and Drug Administration (FDA)-approved uses like pulmonary hypertension.

In addition, Medicare Part D doesn’t cover drugs a person cannot administer themselves. Instead, such drugs falls under the coverage of Part B.

Omeprazole is a drug used to treat various digestive problems. It’s available over the counter in a certain dose and in additional doses with a doctor’s prescription.

Typically, buying it over the counter requires paying out of pocket, but most Part D and Medicare Advantage plans that include drug coverage should cover it when prescribed by a doctor. Additionally, some Medicare Advantage plans might offer an allowance for purchasing it over the counter.