Amid a field of two dozen primary candidates for the 2020 Democratic presidential nomination, the Democratic National Committee has set stiffer requirements for candidates to participate in the third and fourth debates scheduled this fall.

The first of four debates will be held on June 26-27, followed by a second debate on July 30-31, and will be hosted by NBC and CNN respectively. In order to participate, candidates must register 1% or more in three polls conducted between January 1 and two weeks before the debate in which they intend to participate, according to the Democratic National Committee. The polls aren’t required to be national ones. Public polls taken in the first primary and caucus states of Iowa, New Hampshire, South Carolina and Nevada also qualify.

An alternative method to qualify for the first two debate is for a campaign to show it has received donations from at least 65,000 unique donors, and a minimum of 200 unique donors in at least 20 states.

For the third and fourth debates held in September and October, the requirements essentially double, with candidates having to meet both a 2% showing in the qualifying polls and at least 130,000 grassroots contributions.

So far, eight of the 24 candidates in the field have met the criteria to participate in all four of the currently scheduled debates. Six Democratic debates are planned in 2019 with another six planned in 2020.