In early April, three weeks after Connecticut issued shutdown orders, Ken Bodenstein borrowed $148,000 from the federal government to help cover payroll expenses at the Westport day care center he runs with his wife, Kristen.

The small-business loan, along with the Bodensteins’ own cash reserves, allowed the couple to continue to pay their 21 workers for nearly three months. But by June 5, the day the money ran out, only 11 of the 75 children who attended the day care before the pandemic had returned, forcing the Bodensteins to furlough or lay off all but nine employees.

“We were just about to hit break-even, and then everything collapsed,” Mr. Bodenstein said. The Goddard School of Westport had been open less than a year when the pandemic hit.

The federal government’s Paycheck Protection Program was a hastily created and chaotically executed effort to preserve jobs through what lawmakers initially believed would be a sharp but short disruption. Since April, it has injected $523 billion into the economy, allowing small-business owners to stay afloat and keep employees on payrolls.

But with the program set to end Saturday and an economic rebound nowhere in sight, the looming question is: What happens to the millions of workers who have no jobs to return to, and the struggling businesses that employed them?

The numbers are already dire.

On Thursday, the government reported that nearly 1.2 million Americans filed for state unemployment benefits last week — the 20th straight week that new jobless claims have topped one million, although it was the lowest weekly total since March. Economists estimate that 30 million Americans are unemployed. By the time the economy gets back on track, which could take months if not years, entire industries — especially restaurants, bars, hotels, movie theaters, concert venues, gyms and other fields dominated by small businesses — could be decimated, shrinking the pool of available jobs.

So far, there is little agreement in Washington about how to continue to help millions of floundering businesses. Lawmakers are considering extending the P.P.P. in some form. Senate Republicans have proposed letting companies whose sales have fallen by 35 percent or more get a second loan. Other ideas kicking around in Congress include expanding existing low-interest loan programs offered by the Small Business Administration and increasing tax credits for companies that retain workers. Lobbyists are also pleading for bailouts for specific hard-hit industries.

“There’s absolutely a need for more help in some industries,” said Carson Lappetito, president of Sunwest Bank, a regional lender based in Irvine, Calif., that has made more than 2,000 P.P.P. loans. “In the hotel and restaurant and hospitality sectors, those areas have been completely hammered.”

Sunwest, like many other banks that were the main conduits through which P.P.P. money flowed to small-business owners, stopped making loans weeks ago. Mr. Lappetito said demand had fallen off and the bank wanted to focus on other business areas. On Monday, when the S.B.A. begins accepting applications from banks to have their small-business loans forgiven, the complexities of the process are likely to further bedevil lenders and borrowers. Sunwest has around 100 forgiveness applications from borrowers that it’s currently reviewing.

Small businesses employ nearly half of America’s nongovernment workers, and the paycheck program preserved at least 1.4 million jobs through early June, a recent economic analysis concluded. More than five million companies received loans, averaging $102,000 each.

There was a frenzied rush when the program began in April: The fund’s initial $342 billion ran out in just 13 days, stranding hundreds of thousands of applicants and prompting Congress to add another $310 billion. A chunk of it went fast, but months later, more than $125 billion remains unspent.

Lenders said demand slowed because nearly every eligible business that wanted a loan was, in the end, able to get one. But as the economic downturn became prolonged, strict rules about how the cash could be used also made P.P.P. loans less attractive for some business owners. For a loan to be forgiven, most of the money had to be used to pay workers, rather than on other expenses like buying protective equipment or renovating spaces to accommodate social-distancing rules — which became more important for businesses trying to adapt to the new reality.

Jon Winick, chief executive of Clark Street Capital, a firm that advises lenders, called the program a “successful bipartisan effort.” It was created in a hurry based on expectations that the economic recovery would be “V-shaped” — with a sharp dip, followed by a sharp rebound within a brief period — that eventually proved wrong, he said. However, the program “did provide a bridge for thousands of businesses to stay in the game long enough to make it to the other side,” Mr. Winick said.

A bridge was exactly what the relief loan provided for Bob Starekow, the co-owner of two restaurants in Frisco, Colo., a resort town with heavy winter and summer tourism. The P.P.P. loan he got in May allowed him to keep paying his 28 workers while his restaurants, the Silverheels Bar & Grill and Kemosabe Sushi, were closed.

They reopened in June, and business is running profitably, although at a smaller scale, Mr. Starekow said. To cut costs, he slashed his menu. His restaurants could seat about 200 people indoors, but are now mainly using their 90 outdoor seats. Mr. Starekow has not had to lay anyone off, but he has not hired the 20 or so additional people he normally would to handle the summer demand. He worries about what cooler weather will mean for foot traffic.

“I’m not concerned about up or down with revenue,” Mr. Starekow said. “I’m concerned about broke or not broke.”

Mr. Starekow thinks he can make it without more government aid, but others said they would welcome another P.P.P. loan if it were available. At A&J Transportation, a trucking company in Ada, Okla., sales are down sharply from last year, and the company is struggling to stay in the black.

A&J got a $699,000 loan in April and used it to keep paying more than 70 drivers through early June. But after the money ran out, around 30 drivers quit. A&J, which used to work exclusively on oil fields, shifted to over-the-road trucking after the pandemic shut down the state’s oil production. Many of its drivers — who had mostly been paid to stay home while the company hunted for new contracts — did not want to do long-haul work, said Dana Sanford, the company’s office manager.

Now, the company is desperate for workers. “Any driver that wants a job, we’ll give them one,” Ms. Sanford said. If A&J got another loan, she said, the company would use it to meet payroll costs and free up money for other expenses.

Mr. Bodenstein also said a second round of funding would be a godsend for his day care center. For the two months it was closed, his school had zero revenue, but his landlord refused to defer or discount the space’s $30,000 monthly rent. Utilities, insurance and other expenses add $10,000 more to his monthly overhead. A $150,000 disaster loan from the S.B.A. helped him catch up on bills and stave off the eviction notice his landlord sent after he fell two months’ behind, but he’s still trying to dig out from the crater left by the shutdown.

Mr. Bodenstein also got caught by a midstream change in the P.P.P. rules, one of many that have frustrated both borrowers and lenders. Congress initially required that borrowers seeking to have their loans forgiven spend all of the money within eight weeks. So Mr. Bodenstein did what Congress intended: He paid all of his workers to stay home while his business was shut, and kept them off the unemployment rolls.

But Congress later loosened those rules, allowing borrowers to instead take months to bring back their employees and use their loan funds. By the time that change happened in early June, Mr. Bodenstein had already spent his money.

“I felt like it was unfair,” Mr. Bodenstein said. “Those of us who did the right thing and followed the spirit of the program were penalized.”