Field narrowed for Thursday's Democratic presidential debate on Channel 2

ABC News' Democratic Debate will air Thursday at 8 p.m. on Channel 2

Democrats vying for the White House in 2020 are entering a new phase of the election cycle as the primary season deepens ahead of the third Democratic debate.

The first two rounds of debates earlier this summer were critical paths to breaking out from the pack before millions of voters. Now, the third face-off, with more stringent qualifying rules, will perhaps be an indication of the candidates with staying power in the grueling marathon primary.

Here's what you need to know about the upcoming debate:

When is the 3rd DNC debate?

The third Democratic primary debate, hosted by ABC News in partnership with Univision, is slated for Sept. 12 in Houston. The upcoming matchup will take place at the Texas Southern University, a public, historically black university, and will air on Channel 2.

Who is qualified for the 3rd debate?

The 10 candidates certified by the Democratic National Committee to participate in the debate will appear on stage in the following order, from left to right:

Minnesota Sen. Amy Klobuchar
New Jersey Sen. Cory Booker
South Bend, Indiana, Mayor Pete Buttigieg
Vermont Sen. Bernie Sanders
Former Vice President Joe Biden
Massachusetts Sen. Elizabeth Warren
California Sen. Kamala Harris
Entrepreneur Andrew Yang
Former Texas Rep. Beto O'Rourke
Former Housing and Urban Development Secretary Julián Castro

What is the format for the 3rd Democratic debate?

The presidential hopefuls will have one minute and 15 seconds for direct responses to questions and 45 seconds for responses and rebuttals. Candidates will have the opportunity to deliver opening statements, but there will be no closing statements.

How do candidates qualify for the 3rd debate?

The Democratic National Committee announced more rigorous qualifying rules earlier this year for the fall debates in September and October: Candidates must cross both the polling and grassroots funding thresholds.

In order to qualify, candidates must reach 2% or more in at least four national polls or polls conducted in the early voting states of Iowa, New Hampshire, South Carolina and/or Nevada and publicly released between June 28 and Aug. 28. Candidates are also required to receive donations from at least 130,000 unique donors over the course of the election cycle, with a minimum of 400 unique donors per state in at least 20 states. Qualifying donations and polls must be received by 11:59 p.m. on Aug. 28 for the September debate.

Any candidates’ four qualifying polls must be sponsored by one or more of the following organizations approved by the DNC: The Associated Press, ABC News, CBS News, CNN, the Des Moines Register, Fox News, Monmouth University, NBC News, The New York Times, National Public Radio, Quinnipiac University, University of New Hampshire, The Wall Street Journal, USA Today, the Washington Post or Winthrop University. They also must be conducted by different organizations or -- if by the same organization -- must be in different geographic areas.

Who will be left off the stage?

More than half of the crowded Democratic field will be left off stage with the more stringent qualifying rules, and three candidates -- Massachusetts Rep. Seth Moulton, Washington Gov. Jay Inslee and Colorado Gov. John Hickenlooper -- having dropped out of the race in the weeks leading up to the deadline.

Both California activist Tom Steyer and Hawaii Rep. Tulsi Gabbard met the donor threshold before the deadline, but missed the cut after not crossing the polling threshold by Aug. 28.

Colorado Sen. Michael Bennet, Montana Gov. Steve Bullock, New York Mayor Bill de Blasio, former Maryland Rep. John Delaney, New York Sen. Kirsten Gillibrand, Miramar, Florida, Mayor Wayne Messam and Ohio Rep. Tim Ryan are also not participating in the September debate, since they have not met either the donor threshold or the polling requirement.

When was the finalized list of participants announced?

Candidates had until Aug. 28 to qualify and the DNC officially announced the list of participates for the September debate on Aug. 29.

Who is moderating the 3rd debate?

Chief Anchor George Stephanopoulos, "World News Tonight" Anchor David Muir, ABC News Correspondent Linsey Davis and Univision Anchor Jorge Ramos will moderate the debate on Thursday.

Cox Media Group