Almost all the formula bought in the U.S. is made domestically, and imports face multiple barriers.
Low-income households and families of color are getting hit hardest, despite federal efforts to ease the shortage.
When a few companies control most of the market, problems arise.
Supplies of baby formula across the country have been severely curtailed after a February recall exacerbated ongoing supply chain disruptions.
Just four companies make most of the baby formula in the U.S. After a recall and plant closure at one, there's not enough supply to meet the need.