Highway Patrol spokesman Loy Hixson said Reid's injuries were not life-threatening, CNN reported.
The crash occurred about 1 p.m. in the northbound lanes, the Nevada High Patrol said. Reid was taken to University Medical Center, KTNV, Las Vegas, reported.
Reid's office issued a statement saying his security detail took him to University Medical Center Hospital as a precaution and that he "walked in on his own."
"Senator Reid was wearing his seatbelt at the time of the accident. He experienced rib and hip contusions and has been cleared for release by the doctors."
The statement said some of Reid's detail and a staffer "had minor injuries in the accident and were evaluated at UMC."
Reid, 72, was riding in one of four vehicles in a motorcade traveling north on I-15. His vehicle collided with another vehicle, police said.
Reid's wife was not in the car at the time of the accident, his office said.