Speaking to hospital staff members, Bush praised the quality of care received by wounded veterans.
"The problems at Walter Reed were caused by bureaucratic and administrative failures," Bush said. "The system failed you and it failed our troops. And we're going to fix it."
A recent investigation by The Washington Post supported findings of revealed by other media, including United Press International, that some outpatients receiving rehabilitative care at Walter Reed were housed in an old vermin-infested hotel and that many were lost in a maze of red tape as they tried to get care and benefits.
The building the Post report focused on has been closed, Bush said.
Before his remarks, Bush spent some time in a physical therapy room, where he met five patients who had been wounded in Iraq or Afghanistan.
In his remarks, the president described steps that have been taken to improve conditions at Walter Reed, including selecting former U.S. Sen. Bob Dole, R-Kan., who was wounded in World War II, and former Clinton administration Health and Human Services Secretary Donna Shalala to head a special panel on the hospital.