WASHINGTON — Wendee Crofoot lost her job as a fundraiser for a nonprofit in 2011. After exhausting her savings and giving up her Mountain View, Calif., apartment, she ended up working part time as a restaurant cashier.

The low pay qualified her for food stamps, so she signed up. “It wasn’t something I imagined would ever happen,” said Crofoot, 46. “There just weren’t any jobs.”

During the 2007-2009 recession, state and federal governments actively encouraged people like Crofoot to take advantage of the aid. Millions did, and many are still claiming benefits. Enrollment in the Supplemental Nutrition Assistance Program, the formal name for food stamps, remains near record levels, even as the unemployment rate has fallen by half.

“When unemployment was rising people said enrollment would fall sharply when things got better,” said Parke Wilde, an associate professor of nutrition policy at Tufts University in Boston. “That hasn’t happened.”

Another economic downturn could send costs to new heights.

About 45.4 million Americans, roughly one-seventh of the population, received nutrition aid last October, the most recent month of data. Unemployment was 5 percent that month. The last time joblessness fell to that level, in April 2008, 28 million Americans used food stamps, and the program cost less than half of what the government paid out last year.

Even though eligibility rules remained unchanged during the recession, annual spending for the program, administered by states with federal dollars, more than doubled in five years to a record $76.1 billion in 2013.

Several reasons explain the high numbers. Governments have made it easier to sign up for the program. More than 85 percent of eligible food stamp recipients took assistance in 2013, the most recent year of available data, compared with 70 percent in 2008. The higher sign-up rate among those qualified accounts for 8.6 million more people on food stamps — about half of the program’s total increase.

The uneven recovery has swelled the ranks of long-term unemployed and reduced the number of people working or looking for work, further boosting demand. Even for those with jobs, pay may be lower than in the past: In real dollars, SNAP recipients in 2014 had net incomes of $335 a month, the lowest since at least 1989.

“The economy’s recovery is bifurcated,” said Kevin Concannon, the USDA undersecretary who heads the program. That makes food stamps crucial to “a very challenged safety net,” said Concannon, who previously directed state-level food stamp programs in Maine, Oregon and Iowa.

The program became an issue in the 2012 presidential campaign, as Republican contender Newt Gingrich called President Barack Obama a “food stamp president.” It still smolders, with Republicans — including presidential candidate Jeb Bush — saying SNAP needs to be reined in.

States began expanding food stamps during the George W. Bush administration and intensified efforts with the financial crisis.

So-called categorical eligibility, in which qualifying for one aid program automatically enrolls someone in food stamps, allowed potential recipients to bypass federal asset tests. State-administered “heat and eat” programs qualified people who received a token home-heating benefit.

Heat-and-eat expanded SNAP in the subsidized housing where Barb Bailly lives in Madison, Wis. Bailly, 65, took a job bagging groceries after being dismissed from her job with a state agency. She retired at 62 and lives on SNAP and Social Security benefits.

“I was underemployed for years. I used credit cards to make expenses,” she said. “I have to be very careful with my money, but I can get by now.”

Able-bodied, unemployed adults aged 18-49 who don’t have children are supposed to be limited to three months of food stamp benefits during a 36-month period. That can be extended during tough job markets, a provision that’s boosted the percentage of recipients who fit that description to 10.3 percent in 2014 from 6.7 percent in 2007.

Adding adults who should be able to find jobs has helped make the program too expensive to maintain, said Robert Rector, a research fellow at the Washington-based Heritage Foundation, which wants less social spending. It also creates ill will, as consumers see people in grocery checkouts who they think shouldn’t qualify.

Waivers and categorical eligibility are being used in unintended ways to keep federal dollars flowing, he said. “States have become accustomed to putting people in the program,” he said.

Food stamps encourage government dependence, he said.

“Clearly there’s a group of people who are not in the labor force, and 10 years ago they would have been. Now they’re relying on food stamps.”

Suggestions that states and able-bodied workers are gaming the system anger Caitlin Segura, 28, who quit her job to care for her father, who died from cancer last year.

Unable to find steady work since, “I’m not going on a shopping spree for $100 a month” with food stamps, said Segura, who is covering rent on a $1,600-a-month apartment in Vallejo, Calif., with her father’s insurance money. “Food is one thing I don’t have to worry about, even if it means eating ramen for three weeks straight,” she said.