As the partial government shutdown hurtles toward a fourth week, organizations that help California’s food insecure are scrambling to prepare for potential disruptions to the nation’s food stamp program.

This week, the U.S. Department of Agriculture announced it would work with states to keep the Supplemental Nutrition Assistance Program (SNAP) funded through the end of February. That means CalFresh, California’s name for the food stamp program, is safe for now. But food banks across the state, and the food pantries they serve, remain on edge amid concerns the shutdown could last even longer.

“There’s an incredible amount of uncertainty right now,” said Andrew Cheyne, government relations director for the California Association of Food Banks, which represents over 40 food banks throughout the state. “It’s also very difficult to explain that to the people we’re serving in the communities, because it’s such a day-to-day evolving situation.”

Nearly 4 million* Californians receive CalFresh benefits. Of those, about a third have trouble making their food stamps last until the end of the month and rely on food banks to get enough to eat. Even so, food banks provide just one meal for every 12 meals provided by CalFresh. Any delay or disruption to CalFreash could result in an unprecedented demand on food pantries that would be hard to meet, said Monica White, President and CEO of FOODShare, Ventura County’s food bank.

“It’s a vital program,” she said. “SNAP is really the lifeline for the people who are food insecure. We’re the second line of defense for those people. If the SNAP program were to go away, I couldn’t even begin to fathom how we would even begin to fulfill that need.”

Nevertheless, food banks are starting to make plans for such a scenario, Cheyne said, and are in communication with state and county officials about what to do. They also have a cautious eye on other federally funded food programs that could be impacted, including the USDA’s Emergency Food Assistance Program, which provides food banks with food for low-income and elderly people who don’t qualify for food stamps, he said.

Another, even more immediate concern for food banks is the impact of the shutdown on federal workers residing in California. They’re preparing for an influx of workers, such as TSA agents, forestry employees, and U.S. coast guard members, who are living paycheck to paycheck and find themselves unable to buy food, Cheyne said. Some pantries are already providing food for federal workers in need, he said.

“I haven’t spoken with a food bank who hasn’t heard constituent concerns and who isn’t also already preparing or delivering additional food,” he said. “It already is a very serious situation, but one that if the shutdown continues, would be even more difficult to navigate.”

Even if the government reopens by March, the funding arrangement for February could cause problems for people on food stamps, Cheyne said.  The USDA wants states to load February benefits by January 20, which means recipients would get their food stamps more than a week earlier than normal. That could lead more people to run out of their food benefits before they get new benefits in March, the director explained.

Grocery stores that serve CalFresh beneficiaries are another concern. Because of the shutdown, federal officials are unable to recertify stores once their five-year certifications have expired, or accept new stores into the program, Cheyne explained. While not a huge concern in cities and towns with lots of stores, it could pose a big problem in rural communities that have very few grocery stores, he said.

Still, he and others remain hopeful that the most severe impacts of the shutdown on food security can be averted.

“We encourage everyone to please pay attention to this,” he said. “The best solution by far is for Congress and the President to pass the appropriations bill to reopen the government and prevent this crisis from happening in the first place.”

*This story has been updated and corrected. The original version of story stated that more than 40 million Californians receive CalFresh benefits.