Fifteen Republican-led states have declined to participate in a new federal program from the Biden administration aimed at combating food insecurity among low-income families.

Under the Summer Electronic Benefit Transfer program, set to launch this year, states will provide $120 per eligible child to families in the U.S. to help cover food costs through the summer months, when many children are out of school. The Summer EBT program was approved by Congress in 2022 and aims to improve food and nutrition security, access and affordability.

The Department of Agriculture announced on Wednesday that 35 states, all five U.S. territories and four tribes had opted to join the program. But 15 states led by Republican governors have rejected it, The New York Times reported, meaning millions of children are set to lose out on benefits.

The states that decided not to participate are Alabama, Alaska, Florida, Georgia, Idaho, Iowa, Louisiana, Mississippi, Nebraska, Oklahoma, South Carolina, South Dakota, Texas, Vermont and Wyoming.

Summer EBT is expected to provide nearly $2.5 billion in grocery benefits to as many as 21 million children across the 35 states that signed up.

“No kid should have to spend their summer hungry, or without nutritious food,” Deputy Agriculture Secretary Xochitl Torres Small said in a statement. “Summer EBT is a giant step forward in meeting the needs of our nation’s children and families throughout the year, and especially in the summer months.”

Republican governors of the states that opted out of the program had varying concerns, some citing the administrative costs and nutritional standards.

“In the end, I fundamentally believe that we solve the problem, and I don’t believe in welfare,” Nebraska Gov. Jim Pillen told the Lincoln Journal Star, defending his decision not to accept the $40-a-month Summer EBT. The state will still use a different food program that will be the “best route to ensure that Nebraska’s low-income children don’t go hungry this summer.”

Crystal FitzSimons, director of school programs at the Food Research & Action Center, told CNN that providing families with grocery benefits to purchase additional food is “one of the easiest ways to support kids having access to food.”

Governors of states that enrolled in the program have expressed strong support. New York Gov. Kathy Hochul, a Democrat, described the program as “a critical lifeline for families struggling to make ends meet,” and Arkansas Gov. Sarah Huckabee Sanders, a Republican, said Summer EBT was “an important new tool to give Arkansas children the food and nutrition they need.”

Some of the states that chose to participate, such as California and Massachusetts, have also recently adopted permanent programs granting free meals to public school students as part of growing efforts to address food insecurity.

Children who qualify for such free meals in schools are also eligible to receive food aid through the Summer EBT program, CNN reported.

More families experienced food insecurity in 2023 after pandemic-era food aid expired, CBS News reported. A report from the Department of Agriculture found that in 2022, about 17 million U.S. households experienced food insecurity, compared with 13.5 million in 2021, when there was more food assistance available through COVID-19 aid programs.