Howard decided in the late hours on Thursday to forgo another opinion and accept a recommendation to immediately undergo a lower-back procedure with Dr. Robert Watkins on Friday, sources said.
Howard aggravated a piriformis muscle injury in a Nov. 18 game against Portland and has missed 12 of the Wizards' 21 games this season, plus training camp.
Howard, an eight-time All-Star and five-time All-NBA player, has gone from a star to a journeyman in recent seasons. He has changed teams in four consecutive years, bouncing from Houston to Atlanta, Charlotte to Brooklyn and, finally, Washington.
Howard, 32, signed a two-year, $11 million free-agent deal with the Wizards during the summer. Thomas Bryant has replaced him in the Wizards lineup.