NBC's ER (Thursdays, 10-11 p.m. ET) will provide a showcase for several marquee Emmy Award-winning and nominated guest stars this fall with a roster that includes Andre Braugher (Homicide: Life on the Street), John Mahoney (Frasier) and a return appearance of Oscar and Emmy winner Sally Field, who reprises the series role that won her an Emmy.

In addition, John Stamos (Jake in Progress,Full House) will become a series regular when he resumes his previous guest-starring role from last year as Tony Gates, a savvy paramedic and medical student. The Emmy-winning drama series will also feature other prominent guest stars, including Paula Malcomson (Trixie on Deadwood).

Over a span of six episodes beginning in the season's fifth episode, Braugher will play a carpenter who enters the emergency room with a seemingly simple cough. But due to heavy patient congestion, he suffers a stroke while waiting despite the attempts of Dr. Kovac (Goran Visnjic) - and his life eventually falls apart as a result of his paralysis. Earlier, Braugher starred on NBC's Homicide as a tough police murder detective and won an Emmy as Outstanding Lead Actor in a Drama Series.

In an offbeat casting, Mahoney will portray a performing drag queen who wants to assume legal authority for his dying partner's medical care. The Chicago-based actor was nominated several times for an Emmy for his performance as the lovably cranky Martin on NBC's Frasier.

The two-time Oscar-winning Field (Places in the Heart, Norma Rae) returns to play the bipolar and problematic mother of Doctor Abby Lockhart (Maura Tierney) in the second episode. She won an Emmy as Outstanding Guest Actress in a Drama Series for her performance in the role four years ago (and also earned an earlier Emmy for her work in Sybil).

Malcomson will appear in a multi-episode arc as the widow of Gates' (Stamos) deceased best friend and war buddy, a single mother trying to navigate the everyday hardships of child-rearing. She depends on Gates in many ways to provide a father figure for her daughter as well as companionship for them both -- and that includes becoming occasional lovers.

After a stint on daytime's General Hospital, Stamos gained prime-time attention for his role as Jesse Katsopolis in Full House. He later starred in the recent comedy Jake in Progress and the drama series Thieves. In addition, Stamos has starred or appeared in several television movies, including The Reagans, Fortunate Son, How to Marry a Billionaire: A Christmas Tale, Sealed with a Kiss, The Marriage Fool and A Match Made in Heaven. He also was executive producer of the miniseries The Beach Boys: An American Family and a producer on Jake in Progress.

ER will premiere in its 13th season this Fall and will run with 12 continuous original episodes until its cliffhanger in December. The Emmy-winning series will then resume after The Black Donnellys completes its first season.