WASHINGTON >> In November, Michael Ebey, a Secret Service special agent, found himself working another 12-hour shift. Like so many before, it was grueling.

This time, he was part of the detail providing protection for President Joe Biden at the Asia-Pacific Economic Cooperation summit. Pangs of fatigue snaked up his legs from hours of standing on a concrete floor of the Moscone Center in San Francisco, about 3,000 miles from his home.

“I got to the point where I just said, ‘You know, I don’t think I want to do it anymore.’” Ebey put in his papers to retire in January. He was 52 years old.

For months, alarm had been spreading through the executive offices on the eighth floor of the Secret Service headquarters in Washington over the flight of experienced talent like Ebey.

The agency knew it would face an avalanche in 2024. There would be presidential campaigns. Political conventions. A NATO summit. It was looking to be one of the busiest years in the Secret Service’s recent history, even as threats of violence against political leaders were rising.

Service was not ready

“Now more than ever, it is critical that we retain employees,” Kimberly A. Cheatle, the Secret Service director at the time, wrote in an agency-wide email in July 2023.

But instead of growing as the big year approached, the service shrank. At least 1,400 of its 7,800 employees left in the 2022 and 2023 fiscal years, the largest outflow from the agency in at least two decades, federal data show.

This summer, two assassination attempts against former President Donald Trump revealed deep problems in the Secret Service. Failures in technology meant a would-be assassin was able to use a drone for surveillance. Failures in command meant a nearby rooftop was left unprotected for him to climb. Failures in communication meant he was able to fire, even after being spotted.

But agents say one problem underlies all the others: an exodus of the best-trained people.

Their departures, partly rooted in long-standing failures by Secret Service management, have left agents in a kind of permanent state of emergency, lacking the focus, rest and training necessary to do their jobs well, more than two dozen current and former employees told The New York Times.

Among the reasons they leave:

• Crushing amounts of overtime work, often assigned at the last minute and sometimes without pay.

• An initiative to rehire retired Secret Service agents, which backfired by spurring more employees to retire so they could be paid a salary and a pension at once.

• Perceptions of favoritism in promotions and hiring, including an episode in which the agency’s chief uniformed officer moonlighted as a real estate agent for subordinates, who then won promotions.

• Unheeded pleas from agents to rapidly embrace new technology like drones that could improve protection efforts and ease the workload.

The loss of so many valuable agents might be less of a crisis if enough people — and the right people — were ready and waiting to take their place. But management had not solved that problem either.

Recruiting standards slumped, longtime agents said.

The Secret Service and top officials at the Department of Homeland Security, which oversees it, acknowledged some of the problems and said in interviews that they were taking them seriously.

Ronald L. Rowe Jr., the service’s acting director, said the agency needed to rapidly expand the number of trained agents, including sharpshooters and other gun carriers, and acquire more advanced technology to confront growing threats from domestic and foreign actors.

The Secret Service has managed to hire enough agents in recent months that the workforce is growing again. Congress last month also allotted an additional $231 million to cover overtime and other costs for special agents and to acquire more drones, among other equipment.

But dozens of current and former agents told the Times that the agency was still far from solving the underlying problem.

The service had struggled with overwork causing departures, causing more overwork, for at least a decade.

While some junior officers were eligible for extra pay, at time-and-a-half, more senior officers earned only their regular hourly wage for additional time.

Even worse, because of a federal salary cap, many officers received no additional pay at all after a certain point.

Congress moved to address the problem, passing legislation in 2016 that raised the pay cap for agents on protective details, with the maximum compensation as of 2024 set at $221,145.

But some agents were forced to work so much overtime that they still reached the new, higher pay cap.

The Federal Law Enforcement Officers Association conducted a survey last month of Secret Service agents at the request of the Times: 68 of the 153 agents who responded reported that they had “maxed out” last year, missing as much as $30,000 in overtime.

The years leading up to 2024 were supposed to be a period of growth: Secret Service leaders had asked Congress for tens of millions in increased funding to increase its overall staff to 8,305.

No funding growth

Instead, agents responded to their conditions by voting with their feet: 283 Secret Service employees quit, 308 retired, and another 169 accepted jobs at other federal agencies in 2022, data show.

The Secret Service was losing full-time staff members at a far faster rate than several other federal law enforcement agencies, according to data analysis for the Times by the Partnership for Public Service, a nonprofit group.

And a series of management failures undermined efforts to bring in new agents.

One mistake started with a simple-sounding plan: With funding from Congress, the service about a decade ago began to offer retirees a sweet deal: Keep your pension, but come back and collect a salary on top of it.

Plan backfired

The prospect of two incomes was so attractive that it led more agents to retire, Secret Service officials acknowledge. First, the agents disappeared from the workforce for months, using stored-up vacation days and waiting for retirement papers to be processed.

Then, when they returned, supervisors often sent the so-called rehired annuitants to work desk jobs, far from the protective assignments the agency most needed to fill, according to four former officials.

Agency bosses tried to fix it. After Cheatle took over the agency in 2022, she moved to cut the pay that certain new participants could receive to reduce the incentive for them to retire early. And she ordered closer supervision of how the rehired agents were being assigned.

The agency also faced a disillusioned workforce, with the widespread perception that the promotion system was at times driven more by personal connections than merit.

In 2019, a Secret Service veteran named Alfonso M. Dyson became the second-in-command of the uniformed division.

While in that job, Dyson also moonlighted as a real estate agent in Maryland. Records show he represented at least three of his subordinates in buying or selling homes.

Dyson was promoted in January 2022, becoming chief of the uniformed division. After that, two of his subordinates who were former real estate clients were promoted, according to Secret Service records. Promotions are supposed to be based on merit, but the chief helps pick officers who receive them.

Dyson, who retired last year, declined to answer detailed questions.