With just over a week before the qualification deadline, six candidates have cemented their spot on the next debate stage.

Senator Kamala Harris was qualified but dropped out of the race on Tuesday. That same day, Tom Steyer, a billionaire businessman and political donor, became the latest addition to the sixth 2020 Democratic presidential debate, which will take place December 19 in Los Angeles.

According to a CBS News analysis, the following six candidates have already qualified:

• Former Vice President Joe Biden

• Mayor Pete Buttigieg

• Senator Amy Klobuchar

• Tom Steyer

• Senator Bernie Sanders

• Senator Elizabeth Warren

The bar to qualify has been raised once again. Candidates need to prove that they have at least 200,000 unique donors, including at least 800 in 20 different states, U.S. territories or the District of Columbia. That's an increase from 165,000 last month. They also have to reach either 4% in at least four national or early-state polls or reach 6% in two early-state polls. That's an increase from 3% and 5%, respectively.

Presidential hopefuls have until 11:59 p.m. on December 12 to meet both donor and polling requirements. 

The debate will be hosted by PBS NewsHour and Politico.

Ten candidates took the stage for November's debate in Atlanta. Previous debates have taken place in Detroit, Houston, Miami and Westerville, Ohio.