Frank DiMaio had the cash, a signed contract and $230,000 sitting in escrow. He still lost the house he wanted to buy.

The orthopedic surgeon, who recently hung up his scalpel after four decades, spent much of this year trying to swap the Old Brookville estate he and his wife have called home for about 25 years for something smaller on Long Island’s North Shore.

Instead, the couple got a front-row seat to the most cutthroat housing scrum in the country.

“I’ve never experienced anything like this,” DiMaio told The Post.

He’s got plenty of company.

Redfin has crowned Nassau and Suffolk counties the strongest seller’s market in America again and again, most recently clocking roughly 36% fewer sellers than buyers. Across most of the country, the pendulum has swung the other way, with 39 of the nation’s 50 biggest metros now favoring house hunters.

On Long Island, nobody seems to have gotten the memo.

The DiMaios thought they’d scored this summer when the sellers of a luxury townhouse in Woodbury accepted their $2.3 million bid on a $2.4 million listing. They signed on a Tuesday and wired the deposit first thing Wednesday. By Thursday afternoon, the deal had evaporated.

“By the time 4 o’clock came, we were told they’re not signing the contract,” DiMaio said. “They got another offer … and they never gave us an opportunity to match the price.”

To rub salt in the wound, the couple’s deposit stayed tied up while Wall Street rallied. 

“And by the way, that money that was in escrow, the $230,000, we didn’t get it back for 10 days,” he said. “I could have made money on that money.”

Their agent, Joe Scavo of Douglas Elliman, said last-minute reversals have become part of the game. 

“In the 25th hour, the seller’s attorney just emailed us and said they were going with a different offer,” Scavo recalled.

The other side of the ledger told the story just as loudly. Once the DiMaios allowed Scavo to show their Old Brookville spread before it even hit the open market, buyers came running. (Ultimately listed for $4.15 million, its sale is currently pending, though its sale price isn’t yet known.)

“We had two bids over $4 million in 36 hours for the home, and we had no place to go,” DiMaio said.

They finally landed a fully renovated home in an Oyster Bay homeowners association listed at $1.99 million. They offered the full ask and heard nothing. They tacked on another $100,000. More crickets. About five days later, the sellers took $2.1 million.

“And we thought by coming in full price, we were being somewhat generous,” Scavo said. Instead, he recalled, the message from the other side was that “full price right now is just not enough.”

DiMaio still can’t get over it. “Who in their right mind would make a first offer of more than what the asking price is?”

On Long Island these days, plenty of people.

Desperate buyers are scrapping mortgage and inspection contingencies and taking homes as is. 

“Sometimes they’re even taking it furnished if that will help the seller make a decision,” Scavo said.

The frenzy isn’t confined to the mansion set. David Cohen of Corcoran SRG Residential, who works the Woodbury and Syosset markets along with Melville and Dix Hills, has the receipts.

A home at 80 Joyce Road in Plainview listed for $999,000, drew six offers and closed $151,000 over ask, at roughly $1.15 million. Over in Melville, 155 Altessa Boulevard hit the market for $1.59 million, pulled in about four offers and went for $220,000 above asking, or roughly $1.82 million.

Cohen said he’s currently juggling a townhouse priced below $1 million that has drawn six offers. “We had 25 people come to the house in two days,” he said.

“It’s just been pretty remarkable to see,” he added.

Agents point to a perfect storm. There’s virtually no open land left to build on, so buyers are fighting over the same aging housing stock. 

“Everything you’re seeing is just recycled inventory,” Cohen said.

Meanwhile, homeowners sitting on rock-bottom mortgage rates from years past aren’t budging.

“If you’re sitting on a property where your interest rate is 3 or 4, or even 4.5%, and now the rates are 7, well then as a seller, you’re thinking twice about buying a house at a 7% interest rate,” Scavo said.

Rather than move, many are simply renovating. 

“The contractors are celebrating because everybody’s remodeling their homes because there’s no place to go,” DiMaio added.

Even new construction gets gobbled up on contact. DiMaio said a 55-and-over townhouse community in East Northport, with two-bedroom units around $700,000, blew through its second phase before he could tour a model. 

“They literally sold out during the second phase in like six weeks,” he said.

Demand, meanwhile, keeps pouring in from the five boroughs. Cohen estimated the overwhelming majority of his buyers are fleeing Manhattan, Brooklyn or Queens, or are Long Islanders trading up. Sky-high city rents have shrunk the gap between renting and owning, he said, and hybrid schedules make a two- or three-day commute far easier to stomach.

“It’s like, why not? If you have the down payment, why not spend it on a home?” Cohen said.

At the high end, Scavo is even seeing Hamptons money head west. One recent buyer, he said, was “coming out of a $28 million house out of the Hamptons” for a newly built 7,500-square-foot home in Brookville. 

“Maybe we could get that same lifestyle here on the North Shore,” Scavo said of the buyer’s thinking.

Cohen cautioned that conditions vary block by block and noted activity has cooled slightly heading into the holidays, as it typically does. 

“A town on the south shore of Nassau County is very different from a town on the north shore of Nassau County,” he said.

Still, his advice for anyone wading in is to bring a war chest. Scavo agreed.

“You have to be very strong with your finances,” Scavo said. “If you’re not, you’re going to be outbid and you’re going to be left on the sidelines for sure.”