Dr. Joseph from Colorado Springs, Colorado, was kidnapped at gunpoint Wednesday along with two other members of non-profit group Morning Star Development, while returning from a rural health clinic near Kabul, CNN reported.
According to CNN, there were conflicting reports about who was responsible for the kidnappings. While the NATO-led International Security Assistance Force has blamed the Taliban, two local Afghan officials told CNN it was smugglers.
The BBC said Joseph was rescued by US and Afghan forces in a joint operation.
Agence France-Presse reported that US soldiers killed seven Taliban insurgents in the pre-dawn raid to rescue Joseph.
The mission was launched after intelligence showed Joseph was in "imminent danger of injury or death," AFP said, citing a statement from ISAF.
General John Allen, commander of US and ISAF forces in Afghanistan, said: "Today's mission exemplifies our unwavering commitment to defeating the Taliban."
"I'm proud of the American and Afghan forces that planned, rehearsed and successfully conducted this operation. Thanks to them, Dr Joseph will soon be rejoining his family and loved ones."