The Department of Transportation is launching a panel to clarify which airlines will seat children under 13 along with an accompanying adult at no extra charge in the latest push by the Biden administration to crack down on hidden corporate fees.

The department said it has received several complaints in which children, including one as young as 11 months, were not seated next to an accompanying adult. The DOT conducted a review of airline family seating policies and found that airlines did not guarantee that young children would sit next to an adult, even though they generally had policies to do so.

Transportation Secretary Pete Buttigieg said in a statement on Monday that no US airline guaranteed free family seats as recently as a few months ago. In recent weeks, carriers, including United, Border and American Airlines have changed their policies around family seats.

“Parents traveling with young children should be able to sit together without an airline forcing them to pay junk fees,” Buttigieg said, adding that the department had lobbied airlines to guarantee fee-free family seats. «All airlines should promptly do this, even as we move forward to develop a rule making this a general requirement.»

President Joe Biden went after «junk fees» in the past month state of the union, saying that airlines «can’t just treat your child like a piece of luggage.» In its statement Monday, the Transportation Department said it is developing a rule that would prevent airlines from charging families to sit together. Last summer, the Department urged airlines to do «everything in their power» to seat children 13 and under with an adult at no additional charge.

Last month, several Democratic senators introduced the Law of families that fly together to ban airlines from charging families more to sit together. The Biden administration plans to submit additional proposed legislation on the issue to Congress in the coming weeks, according to the DOT statement.