The move comes after a knee injury to regular punter Chris Jones, who was hurt in the Week 3 victory over Tampa Bay. Jones did not participate in Wednesday's walk-through practice and will most likely miss two weeks with a sprained knee.
A roster move is needed to make room for Moorman and that could include putting Jones on injured reserve or releasing another player.
An undrafted free agent out of Pittsburg State, Moorman debuted in 2001 and had played in 179 consecutive games for the Bills. He was the franchise leader in punt average at 43.9 and also had 243 punts inside the 20. But he struggled this season, with just a 32.7-yard net average.
"We were hoping to get more consistency and we were not able to get it," Bills coach Chan Gailey said of the team's decision to release Moorman. "He had a great preseason, he just was not able to get it back."
Through three games, Jones was having a solid start to the season. He is fourth in the NFL with a 44.4-yard net average and he has five punts downed inside the 20.
Opponents have averaged just 4.4 yards per return on Jones punts, second fewest in the NFL.
Moorman was also the Bills' holder and could do the same for the Cowboys. Jones was the holder for kicker Dan Bailey, but there is uncertainty there now with Jones' injury.
Quarterback Tony Romo has been the Cowboys' holder in the past.