McCabe agreed to a two-year $5.7 million contract Saturday, a day before his scheduled hearing. Ullmark agreed to a one-year $1.325 million contract a day after his hearing, but before an arbitrator issued a decision.
Though the Sabres avoided the players potentially being awarded more expensive contracts, the deals push Buffalo about $1 million over the $81.5 million salary cap. That puts the team in a position to have to create additional space before the season opens in early October.
The 25-year-old McCabe has four full seasons of NHL experience since being selected by Buffalo in the second round of the 2012 draft. He had four goals and 14 points in 59 games, and ranked fifth among Sabres defensemen in averaging just less than 19 minutes of play last season.
Ullmark had a 15-14-5 record and two shutouts over 37 games in his first full NHL season, while splitting the goalie duties with Carter Hutton. The 26-year-old from Sweden struggled down the stretch by going 2-9-1 over his final 12 appearances.