Cpl. Wassef Ali Hassoun arrived aboard a C-17 transport and was immediately whisked away in a green ambulance to nearby Landstuhl Regional Medical Center, said Air Force Master Sgt. Jon Hanson.
He was expected to stay 3-4 days for "debriefing and evaluation" before returning to the United States, hospital spokeswoman Marie Shaw said.
Hassoun is out of danger, but he is not out of trouble, reports CBS News National Security Correspondent David Martin In fact, he's under investigation as a possible deserter.
Technically in time of war, desertion is punishable by death, but nobody's talking about that right now," said Martin at the Pentagon. "Everybody's just trying to figure out what the heck happened here."
"His health and mental state are the primary concern," said Maj. Tim Keefe, a spokesman for the Marine Corps in Germany. "As well, he needs to be debriefed by specialists."
Hassoun, 24, was reported missing June 20 from his base near the troubled city of Fallujah. On Thursday, he arranged with American officials to pick him up in Beirut and bring him to the U.S. Embassy, according to U.S. officials.
While he was missing, conflicting reports emerged about Hassoun
first that he was beheaded, then that he was alive.
Arab television on June 27 showed a videotape of him blindfolded, a sword held above his head.
In the latest twist to Hassoun's story, there was speculation he might have deserted his base and headed to Lebanon when he was abducted. The Navy was investigating whether the entire kidnapping might have been part of a hoax.
Before he boarded the jet in Beirut, Hassoun embraced some people and shook hands with others. His mother, Halimeh, and wife, Rana, were at the airport to see him off, Hassoun's brother, Sami, told The Associated Press.
The circumstances of Hassoun's return to Lebanon from Iraq and how he ended up at the embassy remain unclear. The Lebanese-born Muslim "came voluntarily and remained at the embassy while embassy and Department of Defense officials worked out the arrangements for his departure," an embassy statement said Friday.
The embassy thanked the Lebanese government for its "support and cooperation in facilitating his departure."
When Hassoun vanished, the Marines initially said he was on "unauthorized leave" but changed his status to "captured" after a videotape of him blindfolded surfaced a week later. On Friday, the Pentagon said his official status had changed from "captured" to "returned to military control."
Sami Hassoun told the AP that the family met the Marine at the U.S. Embassy late Thursday.
"He appeared a bit uneasy and missed his family but was relieved to see us," he said.
Hassoun's other brother, Mohamad, said Thursday at his house in West Jordan, Utah, that he had spoken briefly with him by phone but couldn't offer details about his disappearance.
"He sounded OK. I was told that he has lost some weight, but he is well," he said.
Also Thursday, a gunfight broke out between members of Hassoun's clan in his home city of Tripoli and business rivals who called them American collaborators because Hassoun joined the Marines. Two people were killed.
Mohammed Hassoun, the man accused of killing the two men, surrendered to police later Thursday and was being questioned, security officials said.
His capture was claimed by a group calling itself "Islamic Response," and came during the tense days before the U.S. transfer of sovereignty to an interim Iraqi government June 28, a period of increased abductions and killings of foreigners and attacks on U.S. forces.
A statement on an Islamic militant Web site Saturday claimed Hassoun had been beheaded, following similar slayings of an American businessman and a South Korean translator in Iraq and an American contractor in Saudi Arabia. The next day, a statement on another Islamic Web site denied he had been killed.
There also has been speculation he might have deserted his base for Lebanon when he was abducted. The Navy was investigating whether the entire kidnapping might have been a hoax.
"It would be fair to say they're not ruling that out," Marine spokesman Maj. Nat Fahy told the AP.
"The circumstances regarding his whereabouts between June 19 and July 8 are under investigation by the Naval Criminal Investigation Service," a Defense Department statement said.
A neighbor in Tripoli said Hassoun left Lebanon for Utah in 1999, joining his parents and brother. Educated in Lebanon at American schools, he joined the Marines in 2001. He married an American woman two years ago, but they divorced.
The neighbor and a distant cousin, Abdullah Hassoun, said the Marine married a cousin in Lebanon by proxy several months ago. His father signed the marriage contract for him, which Islam permits.