For individuals who received a Pfizer-BioNTech or Moderna COVID-19 vaccine, the following groups are eligible for a booster shot at 6 months or more after their initial series: 65 years and older Age 18+ who live in long-term care settings Age 18+ who have underlying medical conditions Age 18+ who work or live in high-risk settings https://www.cdc.gov/media/releases/2021/p1021-covid-booster.html