Prescription Drug Coverage

Ampicillin (Principen/Omnipen) Medicare Coverage

You may be able to find Medicare plan options in your area that cover Ampicillin. Learn more about Ampicillin and find Medicare Advantage plans in your area that cover other prescription drugs.
Chemical name: Ampicillin

Brand name: Totacillin, Omnipen, Penbritin, Principen, Polycillin

Typical dosage: 500mg

Typical type: Capsule1

Ampicillin is a medication used to treat many types of infections. Ampicillin is available only its generic form, and it comes as an oral capsule, an oral liquid and an injection.

Ampicillin is an antibiotic used to treat many different infections including stomach infections, lung infections, blood stream infections, brain infections and urinary tract infections.

Ampicillin is available in its generic form, though it was once also available as the brand name drugs Totacillin, Omnipen, Penbritin, Principen and Polycillin.

Ampicillin is typically taken multiple times a day and is usually used anywhere from 1-3 weeks or longer. Ampicillin prevents bacteria from forming, which allows your infection to heal.

Ampicillin is typically well tolerated, but it can cause upset stomach, vomiting and diarrhea.

How much does Ampicillin cost with Medicare?

Ampicillin coverage and costs may vary based on the specific plan you have, as well as what coverage stage you're in.

Contact your plan carrier or consult your plan formulary for more cost information.

Does Medicare cover Ampicillin?

According to GoodRx, 100% of Medicare Advantage plans and Medicare Part D plans covered Ampicillin in 2023.1

  • Medicare Advantage plans or Part D plans that cover Ampicillin include copay amounts that can range widely from one plan to another. Plan members may also be responsible for meeting a deductible before the plan’s drug coverage kicks in.

  • Medicare Advantage plans that offer prescription drug coverage are called Medicare Advantage Prescription Drug Plans (MA-PD). 89% of 2023 Medicare Advantage plans included prescription drug coverage.2

  • Medicare prescription drugs plans each have their own formulary, or drug list, that details what prescription drugs are covered by the plan and how they are covered.

Drug coverage may vary based on plan availability. You may be able to find Medicare Advantage plan options in your area that cover Ampicillin. We represent carriers such as Humana, UnitedHealthcare®, Anthem Blue Cross and Blue Shield, Aetna, Cigna Healthcare, Wellcare, or Kaiser Permanente.

You can also compare Part D prescription drug plans available where you live and enroll in a Medicare prescription drug plan online when you visit

Additional information

Ampicillin should be taken at least 30 minutes before or 2 hours after a meal. Take each dose with a full glass of water. Try to not miss doses, and complete the entire regimen of ampicillin to fully heal your infection.

While diarrhea is common while taking antibiotics, a severe form of diarrhea can occur. Let your doctor know if you have very bad stomach pain or cramps, loose stools or bloody stools.

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This article is for informational purposes only. It is not healthcare advice, treatment, or diagnosis. It is not an endorsement of or recommendation for this medication. Speak to your doctor or healthcare provider about your specific healthcare needs, including your prescription medications. Only take medication as directed by your doctor.

Coverage and costs of prescription medications will vary by Medicare plan. Not all plans are available in all areas.


Written by Hayden Gharibyar, Pharm.D.

1 GoodRx. Ampicillin. Retrieved October 2023, from

2 Freed M, et al. (Nov 10, 2022). Medicare Advantage 2023 Spotlight: First Look. Kaiser Family Foundation.