TSA allows CPAP, BiPAP and APAP machines in carry-on and checked bags, and American Airlines doesn’t count a CPAP toward its carry-on limit.
At the TSA checkpoint
In a standard lane, the machine, its mask and tubing can stay in their carrying case for X-ray screening, though you may be asked to take the case out of your carry-on bag. In TSA PreCheck, the case can stay in your carry-on.
Liquids for a nebulizer are exempt from the 3-1-1 liquids rule, in reasonable quantities.
Carry-on or checked
TSA says a device with a lithium metal or lithium ion battery should go in your carry-on. A lithium battery device in a checked bag must be switched fully off and protected from turning on.
Does it count toward your carry-on limit?
American Airlines says medical devices, CPAP machines among them, don’t count toward its carry-on limits (as of October 2026). It may still check the device if space is limited, if it doesn’t fit in the cabin or if you don’t need it during the flight.
The US Department of Transportation’s rule for airlines says they must not count assistive devices toward a carry-on limit. The rule doesn’t name CPAP machines, so ask your airline how it treats yours.
CPAP batteries
A lithium ion CPAP battery has the usual limits: up to 100 Wh, or over 100 Wh and up to 160 Wh with the airline’s approval. Spare batteries go in your carry-on only. To work out a battery’s Wh from its mAh and volts, use the Wh calculator.
For lithium metal batteries, the DOT rule lets a portable medical device such as a CPAP use batteries over 2 grams, up to 8 grams, with the airline’s approval. With that approval, up to two such spares can go in your carry-on, carried with the device.
American Airlines says to bring enough fully charged batteries to run your device through the flight, and not to count on a power outlet. Where there are outlets, they may be used for medical devices, sometimes with a DC power adapter.