Every new car seat sold in the United States will soon have to pass a simulated side-impact crash test before it can reach store shelves. The requirement, known as Federal Motor Vehicle Safety Standard 213a, takes effect December 5, 2026, according to the National Highway Traffic Safety Administration.
Under the new standard, manufacturers must test child restraint systems designed for kids under 40 pounds against a simulated 30-mph side-impact collision, using a sled test built around dummies representing a 12-month-old and a 3-year-old, per NHTSA’s rule. The test checks whether a seat keeps a child’s head from striking an intruding door or vehicle structure and whether it limits force to the chest during that kind of crash.
It’s the first time federal regulators have required side-impact testing for car seats at all. Car seats have long been tested against frontal crashes, but not against the sideways collisions that, according to ABC News’ Good Morning America, cause nearly as many child fatalities and serious injuries as frontal crashes do, despite getting far less regulatory attention until now. Side impacts are considered especially dangerous for young children because there’s so little structure between a child in the back seat and the point of impact when another vehicle strikes from the side.
The requirement traces back further than this year: Congress directed NHTSA to develop side-impact protections for child seats under 2012 legislation, and the rule was originally set to take effect in June 2025 before regulators pushed the deadline back to give manufacturers, especially smaller ones, more time to access the specialized testing facilities the sled test requires.
Parents don’t need to do anything differently in the meantime. NHTSA’s rule applies only to car seats manufactured after the December 5, 2026 compliance date: a seat already in a family’s car remains fully compliant and safe to keep using as long as it hasn’t expired, hasn’t been recalled, and is installed correctly. The new standard affects what shows up on shelves going forward, not what’s already installed in the back seat.
For parents shopping for a car seat after the deadline, the practical change will mostly be invisible: the seats will look and function largely the same, just with an added layer of crash-tested protection against a type of collision regulators are only now formally testing for.
The updated standard, formally titled FMVSS 213a, sits alongside a related standard, 213b, that NHTSA finalized around the same time to govern related child restraint requirements, part of a broader federal effort to modernize crash-test rules for car seats that, in some respects, hadn’t kept pace with how vehicles themselves have changed. Manufacturers now have a firm deadline to certify their side-impact performance, and any new seat sold in the U.S. after December 5, 2026 will need to clear that bar before it can legally go to market.
