CNN said its process would air July 18 in the 8 p.m. period of its “Anderson Cooper 360” program. Further details on how the draw will unfold will be released later, the network said.
The second Democratic debate is scheduled for July 30 and 31 in Detroit.
CNN announced Monday that three of its anchors — Dana Bash, Don Lemon and Jake Tapper — will moderate.
The network said that the Democratic National Committee will notify the 20 candidates who qualify for the second debate on July 17.
Under DNC qualification rules, candidates must either register 1 percent support in three approved polls or have 65,000 unique donors to their campaign, with a minimum of 200 different donors per state in at least 20 states.
For the first debate, NBC divided candidates into two tiers, based on polling. Candidates from both tiers were randomly assigned to both nights, in an attempt to even out the two stages.
Still, the result was somewhat lopsided, with most of the candidates leading in the polls — including former vice president Joe Biden, Sen. Bernie Sanders (I-Vt.), Sen. Kamala D. Harris (D-Calif.) and South Bend, Ind., Mayor Pete Buttigieg — placed onstage together for the second night.
Sen. Elizabeth Warren (D-Mass.) was the only top-tier candidate onstage the first night.