The safest place for your child under the age of two on a U.S. airplane is in an approved child restraint system (CRS) or device, not in your lap.

Your arms aren't capable of holding your in-lap child securely, especially during unexpected turbulence. ‘Unrestrained lap children are prone to in-flight injuries, particularly during meal service or turbulence,’ according to a 2019 study by the National Institutes of Health.

The FAA strongly urges you to secure your child in an approved CRS or other approved device for the entirety of your flight. Buying a ticket for your child is the only way to guarantee that you will be able to use a CRS for your child under two years old. For children two years old and older, if you decide to travel with a CRS, or a CARES device (they are certified for air travel only, see below), ensure it comes with the required label indicating “certified for use in aircraft” and your child’s weight and size do not exceed the manufacturer’s device limits.  It's the smart and right thing to do so that everyone in your family arrives safely at your destination. Buckle up your child for the car ride to the airport, on the plane, and when you arrive at your destination.

Lap Children

Although children who have not reached their second birthday are permitted to travel as lap children, the FAA strongly discourages this practice and recommends that you secure your child in an approved CRS in their own seat for the entire flight. 

While there is no regulatory prohibition from using a lap-held restraining device such as a baby carrier or harness-type vest (or other non-approved devices) during the cruise portion of the flight, airlines have policies which may or may not allow the use of those devices. Check with your airline.