At least one of the prisoners, ranking Taliban leader Khairullah Khairkhwa, had direct ties to Osama bin Laden.
Bergdahl was picked up by helicopter in western Afghanistan, near the Pakistan border.
After climbing aboard, the 28-year-old Idahoan, trying to communicate with his rescuers over the roar of the rotors, scrawled "SF?" on a paper plate — asking his rescuers whether they were special forces.
"Yes," one of the men shouted. "We've been looking for you for a long time."
The Army infantryman — himself nicknamed "SF" by his comrades for his gung-ho interest in special-forces tactics — began to weep.
Bergdahl's parents, who had lobbied continuously for his release, had not seen him by Saturday night, but intimated that he faces an arduous recovery from his ordeal.