Am I eligible for a COVID-19 vaccine booster?

If it's been six months or more since your second COVID-19 vaccine shot, you may be wondering whether you qualify for a booster.

In September, the Centers for Disease Control and Prevention endorsed an independent panel's recommendation that older adults, along with those as young as 18 who have an underlying medical condition, receive a Pfizer booster shot.

CDC Director Rochelle Walensky also added a recommendation for a third dose for those in high-risk jobs or settings, such as nursing and teaching. Immunocompromised Americans, like those undergoing cancer treatment, have been able to get a third dose of the Moderna or Pfizer mRNA vaccines since mid-August.

But there has been a lot of public debate and there are different rules for Moderna, Johnson & Johnson, and Pfizer boosters, all of which can add to confusion. So, when is it your turn?

ABC News answers a wide variety of scenarios in the table below to let you know whether you qualify -- and if you don't today, when you might.

New booster recommendations are expected after the CDC advisory panel's meetings on Oct. 20 and 21.

Boosters are intended to return the level of protection to the vaccine's optimal level. Mixing and matching vaccines are not authorized or recommended at this time, but may be in the near future, and if your vaccine or demographic isn't yet eligible for a booster, experts say it's best to wait.

Appointments for all vaccines and boosters can be found at vaccines.gov.