The country music superstars have performed for children who are patients and donated more than $3 million to the hospital during the past five years.
The band, which includes Gary LeVox, Jay DeMarcus and Joe Don Rooney, performed for the children Friday after the announcement and handed out candy during trick-or-treat room visits.
The Rascal Flatts Surgery Center will include new specialized radiology suites to improve treatment. More than 12,700 children undergo surgery at the hospital each year.
Friday's performance started a busy run for the group, which is up for a Country Music Association Award on Nov. 10 and releases a new album Nov. 16.