Dangerous doctors whose licenses have been yanked or suspended in New York or New Jersey are crossing the river and continuing to treat patients, The Post has found.

It can take authorities months to shut down shady MDs, a Post review of disciplinary records in both states from Jan. 1, 2018, to the present found.

New York’s medical oversight board took from a few weeks to several months to stop 14 doctors from practicing after New Jersey deemed them unfit to work or limited their licenses.

Worse, New York has yet to act on two accused quacks.

New Jersey, meanwhile, hasn’t disciplined five New York docs whose licenses have been revoked, suspended or restricted since October, and the state delayed its discipline for at least one other.

Patient-safety expert Betsy McCaughey, the founder of the Committee to Reduce Infection Deaths, said the slow state systems are in critical condition.

“It could lead to unnecessary additional harm to patients,” said McCaughey, who is also a former New York lieutenant governor.

“In this day and age, you shouldn’t have those delays. All you have to do is send them an e-mail. It’s not like you have to put a letter in a saddle bag.”

Among the doctors still practicing is Manhattan butt butcher Ayman Shahine, who lost his New York license on Jan. 9, when the state Board for Professional Medical Conduct sustained 16 allegations of misconduct against the gynecologist-turned-plastic surgeon, including gross incompetence and negligence.

More than a dozen women have sued him for malpractice since 2013.

Elizabeth Sanchez told The Post that she complained to New York authorities about her liposuction in Shahine’s office. She said that her throat felt like it was closing after she was injected in about 50 places with a numbing agent and that she cried out that couldn’t breathe.

“Oh, you’re fine, honey,” she says Shahine told her.

Sanchez said she passed out and was rushed to Bellevue Hospital.

Gisselle Torres-Figueroa, 19, of Rochester, sought Shahine after watching a clip of singer K. Michelle being treated by the doc.

Torres-Figueroa got a $10,000 loan and arrived at Shahine’s midtown office on Thanksgiving weekend in 2017 for a tummy tuck and butt lift.

It was a decision she now regrets.

Torres-Figueroa could not get out of bed for almost a month, and has “permanent numbness and burning pain” in her lower back, abdomen and butt.

Connie Zuniga, 29, said Shahine removed fat during her liposuction and pumped too much of it into her behind. He then directed her to swaddle herself in a yoga mat with a book placed on each side of her rear end.

Shahine, who remains licensed in New Jersey, Connecticut, Florida and Georgia, is still taking appointments in New Jersey, according to a woman who answered the phone at his former 34th Street office.

Former patient Dominique Bligen-Singleton exclaimed, “Hell no!” when told Shahine was still operating across the Hudson. The Florida woman says Shahine botched her butt lift at his New York office.

Shahine was unrepentant.

“I’m practicing in three different states outside New York,” Shahine told The Post, refusing to provide specifics. “As long as I’m legal there, I’m doing it.”

New Jersey has also not disciplined Dr. Joseph Pober, a Park Avenue plastic surgeon whose New York license was suspended for 18 months starting Jan. 11 over accusations of negligence and incompetence. He is seeing patients at a Ridgewood, NJ medical spa.

And the Garden State has not taken action against Dr. Chinwe Offor, a neonatologist whose New York license was yanked in January after she was charged with negligence and incompetence in treating four babies at a Long Island hospital, including one “inappropriately diagnosed” as dehydrated and another for whom she “inappropriately ordered” the deadly painkiller Fentanyl.

A hearing committee found her failures as a doctor were “significant and pervasive,” state records show.

Offor told The Post that she was practicing in New Jersey but would not say where and defended her treatment of patients.

“Not every doctor who is disciplined in New York is a bad doctor,” she said.

She said she had not even heard from New Jersey’s medical board.

The New Jersey Board of Medical Examiners gets daily alerts on doctors whose licenses have been suspended or revoked and then reviews the actions taken in other states, typically issuing the same sanctions, according to the state Attorney General’s Office.

Lisa Coryell, a spokeswoman for the office, said she couldn’t comment on specific cases and pending action by the state’s disciplinary panel, the Board of Medical Examiners.

“The board prioritizes cases based on the nature of the allegations and the potential threat to the public,” Coryell said.

New York medical authorities were slow to follow New Jersey’s lead in the scary case of Dr. Anindita Nandi.

The New Jersey board in September found that allowing the Jersey City endocrinologist to continue to practice would be a “clear and imminent danger to the public.”

They suspended Nandi’s license after a patient complained that Nandi was acting strangely in a consultation, delivering a 20-minute lecture on the rules of her practice. Nandi was already under special state monitoring after being hospitalized for a “psychiatric disorder” and was not complying with the program, state records show.

A fellow doctor told New Jersey authorities on Sept. 8, 2018, that Nandi “appeared to be ignoring reality.”

In New York, where Nandi also practiced near the United Nations, patients complained online as recently as Sept. 11, 2018, about her demeanor. One noted in 2017 that she appeared to have mental-health issues.

But New York did not act until Jan. 25 of this year — four months after New Jersey stopped her from practicing. Her license was suspended while the state Board for Professional Medical Conduct conducts hearings.

There is no New York discipline on record for Dr. Mariam Rubbani, whose New Jersey license was suspended in October.

Rubbani worked at an arthritis clinic under probe by New Jersey health officials for poor infection control that led to patients getting septic arthritis.

Rubbani did not respond to a request for comment.

A spokeswoman for the New York state Department of Health said the state receives “real-time notification” when doctors are disciplined in other states and “immediately” starts a probe.

“When that referral suggests the physician poses imminent danger to the public, the physician is suspended pending the outcome of the investigation, and after the investigation, board action is taken against the physician when warranted,” said the spokeswoman, Jill Montag.

The DOH said it had no evidence that Rubbani was practicing in New York or that Nandi saw patients in New York after her Jersey license was pulled.

Doctors with dual licenses who have been disciplined in New York or New Jersey but remain active in the other state: