Elam, the Ravens' 2013 first-round pick, had been designated to return off injured reserve. He sustained a knee injury and had surgery in the preseason that sent him to IR for the Ravens' first eight weeks of the season.
Elam is expected to contribute on special teams and possibly play in nickel defense.
"The way I prepare myself, it won't take long (to get back on track)," Elam said. "I'll go out there Sunday just like I haven't missed (any time). I'm very excited, and I've been preparing myself well."
In his fourth NFL season, Elam has seen action in 32 NFL games, making 26 starts. He has produced 123 tackles, a half-sack, one interception, eight passes defensed, two fumble recoveries and one forced fumble during his career.
To make room for Elam, the Ravens waived cornerback Robertson Daniel.
The Ravens also claimed cornerback Chris Lewis-Harris off waivers after releasing cornerback Will Davis.
The Cincinnati Bengals waived Lewis-Harris on Thursday after he made four tackles, one interception and two passes defensed in seven games this season.