The lead singer of Jefferson Airplane lost half his tongue and his thumb and suffered a paralyzed vocal chord when doctors at a Manhattan hospital botched his heart-surgery recovery, he charges in a lawsuit.

Marty Balin, who co-founded the pioneering 1960s psychedelic rock band and wrote such songs as “Comin’ Back to Me” and “Plastic Fantastic Lover,” was in New York City to promote his new solo album, “The Greatest Love,” with a performance at The Cutting Room in Midtown on March 12, 2016.

But a day before the show, the rocker, then 74, was rushed into the emergency room at Mount Sinai Beth Israel with chest pains, according to his lawsuit filed Thursday in Manhattan federal court.

Doctors at the First Avenue hospital performed open-heart surgery, a triple bypass and a valve replacement. Balin came out fine but required recovery in the intensive-care unit.

His suit claims the 17th Street branch of the hospital, which was in the process of closing, was too understaffed to provide the care he and his wife, Susan, were promised.

“They should have told him, ‘We are closing, so go uptown to Mount Sinai because we can’t handle the aftercare.’ It was like a comedy of errors,” said Balin’s lawyer, David Jaroslawicz.

“They were supposed to have special nurses and special doctors to help the serious patients to get the rehab they needed and to monitor them.”

The lawyer noted that Mount Sinai didn’t have a pulmonary specialist or a critical-care physician on hand.

Things took a turn for the worse when Balin — who also fronted Jefferson Starship, an incarnation of the San Francisco-based Jefferson Airplane, before leaving in 1978 — had to undergo a tracheotomy due to the hospital’s “negligence,” the suit claims.

But the invasive windpipe procedure was scheduled too late and was screwed up by a doctor who left Balin with half of his tongue and a paralyzed vocal chord.

“For someone who is a singer, losing your tongue is very serious,” Jaroslawicz said.

Balin’s suffered permanent injuries to his left hand, too, which threw his musical career into question.

Susan Balin repeatedly complained to hospital staff about the singer’s care, including that his thumb was turning blue from an intravenous line that was improperly placed and not monitored, Jaroslawicz said.

Necrosis set in, resulting in Balin losing his thumb.

“He played the guitar for the band, and he lost his left thumb because they hit an artery,” the lawyer said. “No one was watching it by the time it happened.”

The suit said Balin, who also suffered from bedsores and kidney damage, now can’t eat or speak properly. He requires dialysis and can no longer “care for his special-needs daughter” who has spina bifida.

“It was a horror show,” Jaroslawicz said.

In a lengthy phone interview last month with the Marin Independent Journal in California, Balin said the nearly career-ending ordeal was harrowing.

“That was a hell of a two years,” the Tampa, Florida resident said. “It was a pain in the butt but I’m doing good now.”

He said he’s been busy making music — and hopes to go back out on tour.

“I’m writing songs left and right,” he said. “I’m finishing two new albums and the guys in my band are eager to get back on the road.”

In a statement, Mount Sinai said it couldn’t comment on the specifics of Balin’s case, citing pending litigation.

“But we can share our highest priority is delivering the highest level of compassionate care to our patients,” the hospital said.