If you got the Pfizer vaccine, get ready to help increase your protection with a COVID-19 vaccine booster shot. Medicare covers a Pfizer COVID-19 vaccine booster shot at no cost to you if you’re 65 and older OR for certain people at high risk, at least 6 months after you complete your second dose of the Pfizer COVID-19 vaccine series. (Note: Don’t mix vaccines. Your third dose should be the Pfizer vaccine if your first two doses were Pfizer.)

Learn more about who should get a Pfizer booster shot.

There are several reasons why you should get a booster shot. You may have built enough protection after your vaccination earlier this year, but that protection decreases over time against mild and moderate disease (this is called waning immunity). Also, while COVID-19 vaccines remain safe and remarkably effective against severe illness, hospitalization, and death, no vaccine is 100% effective at preventing infection. The Delta variant causes more infections and spreads faster than earlier forms of the virus that causes COVID-19, so we all need to stay on guard.

If you’re unvaccinated or just partially vaccinated, it’s critical for you to get your first round of vaccine shots right away, to lower your risk of COVID-19 and its more severe outcomes. Nearly all cases of severe disease, hospitalization, and death continue to occur among those who aren’t vaccinated.

To get your booster shot, or to start with your first set of vaccine shots, visit Vaccines.gov to find COVID-19 vaccine providers near you.