The Massachusetts congressional delegation is demanding answers from Abbott Nutrition on when strained consumers can see baby formula Similac back on store shelves.

In a letter led by Reps. Lori Trahan, Katherine Clark and Ayanna Pressley sent to the manufacturer Tuesday, legislators said “rationing food for infants who desperately need nutrients to grow up strong and healthy is not an acceptable outcome.” The representatives say their intention is to get more information from Abbott so that families can plan accordingly.

Abbott is the producer of Similac, the exclusive standard baby formula for recipients of the state's Women, Infants and Children Nutrition Program. The families of about 22,000 infants around the state rely on the WIC to find a supply of baby formula.

About 42% of all babies born in Massachusetts are enrolled in the WIC program, through which they get baby formula. But their guardians are facing a slog finding Similac, or any baby formula. The organization gives clients a WIC card, and they buy the product themselves in grocery stores and large retailers. That's difficult in the current crisis. The out-of stock rate reached 43% last week, a 10% increase from April, according to the letter, still not enough to feed children and help parents stock up.

“Our staff has been calling all stores to find formula as well. When our participants call us, we try to help them out, and tell them where they can access it,” said Evelyn Friedman, executive director at Greater Lawrence Community Action Council, which assists WIC recipients in Lawrence, where 95% of babies born last year were eligible WIC participants. The closest Walmart and Target, where WIC recipients can buy Similac, are in Methuen, and they’re constantly running out. Friedman is urging people to call ahead instead of taking public transport and checking themselves, since the store might be out of supply

On Monday, Abbott and the U.S. Food and Drug Administration reached an agreement to restart production at the manufacturer's facility in Stugis, Michigan — the baby formula producer's largest plant, which has been closed since February. Products will ship out from the site in more than a month from now. Few details are available about the agreement, which is subject to court approval.

But Trahan said the baby formula shortage didn’t start with Abbott. The facility shutdown exacerbated an already strained formula supply nationwide.

“We've been tracking lower levels of formula supply since earlier this year,” she said. “But there's no question that the slowdown caused by the closure of Abbott's Sturgis facility has made the formula shortage a crisis, especially here in Massachusetts.”

In the letter, lawmakers asked what steps Abbott is taking in the interim to mitigate shortages and prioritize states like Massachusetts “whose exclusivity agreements through WIC have caused families to suffer from the shortages most acutely.”

They’re also requesting the company outline steps to ensure the shortage doesn’t happen again, and to describe what criteria they’re using to determine who receives formula on a case-by-case basis, and ensure equitable distribution.

Trahan said some families in her district have to drive 30 or 40 minutes to track down Similac or an alternative. “It’s devastating,” she said, adding that not too long ago, she was giving her own children formula.

Trahan wants reform for local families. Federal regulations require state WIC agencies to competitively procure a single infant formula manufacturer for standard formula, according to the Department of Public Health.

Trahan thinks it’s a “flawed system” because of market consolidation.

“I don't think we can outright ignore the effects of extreme concentration in the baby formula market when something like this happens,” she said. “I think long-term, we need more competition, right? We need more options for our families so that when crisis does hit, we're not in this situation.”

Friedman agreed. “It’s really important that there's some more opportunity for getting different varieties of formula so that we don't get stuck in this situation again,” she said.

The Department of Public Health said it has been using waivers from U.S. Department of Agriculture and flexibilities in their Abbott contract to give WIC recipients more options for standard formula, including different sizes of the products and formulas from Gerber, Mead Johnson and store brands. These additional options are set to be in place at least through August.

Francis Grubar, a spokesperson for Trahan, said the representative credits the state for “being agile in responding” to the shortage with these new options.

WIC recipients can ask for formulas other than Similac, but it’s not easy. That requires documentation from a medical provider explaining why another type is needed. A WIC nutritionist performs a dietary assessment to verify the need of the different formula, and the program makes the final decision. If a child is lactose intolerant, there’s also a special formula WIC can provide.

The Massachusetts legislators have asked Abbott to answer their questions by May 20, 2022.

On Friday, the House Committee on Oversight and Reform sent letters to the country’s four largest baby formula manufacturers, which included Abbott, asking how they will increase supply and prevent price gouging. There’s also emergency federal legislation being considered that would address the formula shortage.

“When you’re talking about a denial of people to be housed, to be fed, to take care of their baby, something must be done. And people playing a role in that must be held accountable,” said Pressley, who sits on the Committee, to Boston Black News last week.