He began the season with Washington, where he averaged 6.4 points in 28 games, including 14 starts.
"As we explored opportunities to add to our team after the trade deadline, we felt it was important to prioritize experience and versatility," Hawks coach Mike Budenholzer said. "Kris is a versatile veteran with playoff experience who fits well with our group and within our system. We are fortunate to have Kris join our team and would like to welcome him to the Hawks family."
The Hawks' front-line depth took a hit when center Tiago Splitter, acquired last summer from San Antonio, was sidelined by a lingering hip injury. The team announced last month that Splitter needed season-ending surgery.
The Hawks also assigned guard Lamar Patterson to Canton of the NBA Development League.
Information from The Associated Press was used in this report.