Carlos Price, right, who works as the program director at the Latin American Youth Center, collects donations while welcoming guests for the Rainbow Talent Affair event. Because of the sequester her non-profit could lose $300,000 in federal funds. (Astrid Riecken/For The Washington Post)

With automatic budget cuts looming, George Garrow decided he could no longer put off the inevitable.

Garrow — whose small nonprofit group serves at-risk youth and about 100 veterans — gathered his top aides late last week in the conference room of his L Street office and began to pore over budget spreadsheets.

The mood was grim, and it soon grew worse. As they went over the numbers, they realized that if sequester cuts stay in effect, they will eventually have to get rid of half their staff of 40.

Around the country, nonprofits organizations and others who work with the disadvantaged have been scrambling in recent days to prepare worst-case budget scenarios for the expected 5 to 8 percent cuts in domestic spending called for by the sequester.

Because certain entitlement programs, such as food stamps and Temporary Assistance for Needy Families, were exempted from the $85 billion in automatic spending cuts, the most vulnerable were not supposed to be severely hurt.

But low-income families, seniors and people with disabilities will face “very real impacts,” said Sharon Parrott, vice president for budget policy at the liberal Center on Budget and Policy Priorities and a former Obama administration official.

There will be cuts to a wide range of services for the needy, analysis shows, including Meals on Wheels for seniors, nutrition assistance for mothers and children, rental help for low-income families and programs for the homeless.

Nobody knows if moves to forestall the cuts could happen this month, in the next few months or any time this year, which adds to the uncertainty and stress.

“The insecurity of that — when you’re dealing with human service needs in neighborhood settings — is just crazy,” said Lori Kaplan, the president and chief executive of the Latin American Youth Center, which serves 4,400 youth in the District and Maryland. “No business can run like this.”

Kaplan is facing a loss of between $300,000 and $400,000 in federal grant money, she estimates, forcing some tough decisions at the Columbia Heights center that houses homeless teens and offers domestic violence counseling and job training.

“There’ s no question we will be hit,” Kaplan said. “It’s just a question of when, and by how much.” As many as a dozen homeless teens seeking shelter may have to be turned away, she said.

Advocates say the fact that so many low-income residents may suffer is getting lost amid the debate over the possibility of longer airport lines and whether the Obama administration has hyped its numbers. The spending cuts are kicking in at a time when food banks are facing unprecedented demand and a record 46 million people — 15 percent of all Americans — are on food stamps.

For many whose tenuous hold on daily life can be threatened by small changes, anxiety already has arrived, from a unemployed veteran in the District who may not get bus tokens for job interviews to a senior citizen in Maryland who will soon be getting one less meal a week.

Stephanie Archer-Smith, the executive director of Meals on Wheels of Central Maryland, is facing a loss of $250,000 in funding that provides meals for 1,200 seniors, including many in the Washington suburbs. The organization may have to cut meal service from five to four days a week beginning April 1.

“These people up on the Hill aren’t looking at the complete picture. People’s lives are going to be affected,” said Garrow, who is executive director of the national office of Concerned Black Men. “The elephants have a fight, and the little people and the grass get trampled! That’s what’s happened.”

Garrow’s group runs parenting classes, offers mentoring for youths and helps veterans through the Labor Department-funded Homeless Veterans Re­integration Project , a $38 million program that is vulnerable to cuts.

That the sequester will have such a wide-ranging effect on the poor may come as a surprise, because exempting social safety net programs has been a hallmark of such agreements since Congress first introduced the idea of a “sequester” to force budget savings in the late 1980s. During fiscal negotiations in 2011, for example, when Republicans tried to put Medicaid, the health insurance program for the poor, into the talks, President Obama’s aides refused.

The sequestration will impose cuts to WIC (formerly known as the Special Supplemental Nutrition Program for Women, Infant and Children), a well-regarded supplemental nutrition program that supplies nearly 9 million women and children with foods such as milk and cereal, according to an analysis by the Center on Budget and Policy Priorities.

Since 1997, Congress has committed enough money to the program to provide for all who were eligible. Now, more than 600,000 women, infants and children could be turned away from food by Sept. 30, the end of the fiscal year,the analysis showed.

That shouldn’t happen in Maryland, where Jacqueline Boras, the state’s WIC director, expects to be able to absorb the 5.1 percent reduction in funding.

But she is concerned, she said, that next year the program will not be fully funded, forcing staff to come up with a way to trim 9,000 of the 145,000 currently served. The National WIC Association has begun counseling its member organizations to cushion the cuts by using more store-brand foods, expanding rebates and creating waiting lists for those at least risk of nutritional deficiency.

“I’ve never seen anything like this,” said Boras. “Not knowing what your budget is going to be puts fear in participants and staff. We get questions like, ‘Am I still going to get my WIC benefits?’ ”

In recent days, Clinton Wilson, 56, an unemployed Vietnam veteran from the District, has had the same kind of fear swirling around his head. Wilson moved to the area last fall from Portsmouth, Va., to live with his niece after he was laid off from his longtime job in construction.

Concerned Black Men’s program manager helped Wilson submit online job applications and provided bus tokens to get to job fairs. That assistance is in jeopardy. Wilson’s dream is to become a chef, so in April, with the group’s help, he is scheduled to start a culinary training program sponsored by D.C. Central Kitchen. Now, he worries, he might not have the bus fare to get there.

“The sequester, it might cut a lot of things out, and I really don’t think it should happen,” he said. “I’m very much concerned, and I think the program should continue. They help a lot of people.”

Jennifer Jenkins contributed to this report.