Barr's other writing credits included episodes of Parker Lewis Can't Lose and Weird Science before his longest stint, as one of the main writers for Will & Grace (on eighteen episodes between 1999 and 2004), usually credited as a producer as well (supervising, co-executive, or co-producer). Because of the latter, he shared in the series Emmy Awards win in 2000 for Outstanding Comedy Series. Barr went on to write episodes of Desperate Housewives, The New Adventures of Old Christine, and The New Normal.