Neris got the save in Tuesday's 4-3 win over the Padres, allowing a walk and striking out a batter over a scoreless inning.
The Astros signed Neris to a one-year contract Thursday, Ari Alexander of KPRC 2 in Houston reports.
The Cubs released Neris on Tuesday, Jesse Rogers of ESPN.com reports.
Neris was charged with a blown save Friday against the Blue Jays, allowing three runs on four hits in the ninth inning. He struck out two.
Neris gave up two hits and a walk in a scoreless ninth inning Friday to record his 16th save of the season in a 7-6 win over the White Sox.
Neris (8-4) allowed one run on one hit across an inning of work to take the loss Saturday against the Cardinals.
Neris earned the save in Friday's 6-3 win over the Cardinals, striking out two while issuing a walk over 1.1 innings.
Neris (8-2) pitched a scoreless inning of relief to earn the win in Sunday's 2-1, 10-inning win over the Diamondbacks. He walked one and struck out one.
Neris struck out the only batter he faced to earn the save in Sunday's 5-0 win over the Angels.
Neris worked around a hit and a walk to pitch a scoreless ninth inning in Saturday's 8-1 win over the Mets. He struck out two.