More than 13,000 U.S. army reserves have spent a year or more in medical hold units after being injured in Iraq. Congress is investigating:

Critics inside and outside the Army say "med hold" units are choked with reservists who should have been home much sooner with family or friends. Instead, they find themselves in a system that some Army officials acknowledge was unprepared to handle the thousands of soldiers wounded in combat overseas or injured while training or serving on U.S. military bases.

Shortly after the March 2003 Iraq invasion, when casualties started returning to the U.S., "the system was immediately overloaded," said Col. Lynn Denooyer, an Army Reserve nurse stationed at Fort Carson between March 2003 and August 2004.

Soldiers, veterans' advocates and some lawmakers say that despite recent efforts to beef up medical staffing and speed delivery of care, the Army still hasn't caught up, particularly when it comes to caring for National Guard and Res. erve soldiers.

The purpose of the med-hold program is to allow injured soldiers keep their full-time pay while under review. The problem is, they never leave.

Guard and Reserve soldiers can spend months in med-hold units, unable to return to their civilian lives, while the military decides whether they are fit to serve or must be discharged - and if so, how much pay they should receive.