Fox Business Network's first-ever Republican debate airs Tuesday evening at 9 p.m. ET, with an "undercard" event for the four lower-polling candidates airing at 7 p.m. ET.

The fourth official GOP debate, which will focus largely on economic policy, takes place at the Milwaukee Theatre in Milwaukee, Wisconsin. The main event will be moderated by Fox Business Network anchor Maria Bartiromo, Fox host and executive Neil Cavuto, and Wall Street Journal editor-in-chief Gerard Baker. The "undercard" event will be moderated by FBN anchors Sandra Smith, Trish Regan, and WSJ D.C. bureau chief Gerald Seib.

Eight candidates qualified for the primetime debate by scoring 2.5 percent or higher on an average of four recent national polls: Donald Trump, Ben Carson, Marco Rubio, Ted Cruz, Jeb Bush, Carly Fiorina, John Kasich, and Rand Paul. The main event will last two hours.

The earlier debate will consist of the four candidates who racked up more than 1 percent in polling: Chris Christie, Bobby Jindal, Mike Huckabee, and Rick Santorum.

Both debates will broadcast on the Fox Business Network cable news network, which can be found on certain subscription packages. The showdowns will also air live on FoxBusiness.com, and unlike previous debates, the digital live stream will not require authentication from a cable provider.

However, if you so desire to view the debate on television, some cable and satellite providers have agreed to make Fox Business Network available to all subscribers just for the debates.

The debate will be simulcast on Fox Business's SiriusXM radio channel 113.