The 21 ½-hour Labor Day weekend tradition will be hosted by veteran entertainer Lewis and co-hosts Allison Sweeney, Nancy O'Dell and Jann Carl. Guest co-hosts will include "American Idol" and Broadway vet Ace Young; actor, comedian and former Hairspray star John Pinette; "American Idol" executive producer and "So You Think You Can Dance" co-creator Nigel Lythgoe; actor/comedian Richard Belzer; and actor Brandon Barash.

Tyce Diorio of "So You Think You Can Dance" will choreograph the opening number, and the telethon will also feature performances from the casts of Memphis, Rock of Ages and Million Dollar Quartet, as well as numbers from the Las Vegas shows Elvis (Cirque du Soleil), Paris by Night and Vegas! The Show.

Broadway and cabaret star Maureen McGovern, Barry Manilow, David Archuleta, Enrique Iglesias, Charo, Jack Jones, Lynyrd Skynyrd and Taylor Dayne will also perform.

Cast members from "Glee" and "The Doctors" will also make appearances, as will Tony and Emmy winner Ken Howard, Ray Romano, Patrick Duffy, Carrot Top, Lou Ferrigno and Olympic Gold medalists Bart Conner and Nadia Comaneci.

The telethon will begin Sept. 5 at 9 PM ET and will be broadcast from the South Point Hotel in Las Vegas, ending Labor Day, Sept. 6 at 6:30 PM ET. Check listings for local start and end times, or visit mda.org.