Can You Bring a CPAP Machine on a Plane?

Yes — and it does not count against your carry-on allowance. CPAP, BiPAP, and APAP machines are classified as medical devices by TSA and the US Department of Transportation. You can bring your CPAP in addition to your standard carry-on and personal item, at no extra charge on US airlines.

This is one of the clearest examples of a medical device exemption in aviation — the rules are well-established and consistently applied.

TSA Rules: CPAP as a Medical Device

TSA classifies CPAP machines as medical devices. This has two practical effects:

1. They do not count as your carry-on bag. You can bring a standard carry-on bag, a personal item, and your CPAP as a separate item. TSA will not make you consolidate your CPAP into your carry-on or personal item.

2. They go through X-ray screening. TSA may ask you to remove the CPAP from its bag and place it in a separate bin for X-ray, similar to how you remove laptops. This is routine. The machine itself may be swabbed for explosives — this is also routine and quick.

It helps to arrive at the checkpoint with your CPAP in a bag that makes it easy to separate from other contents. Many CPAP travel cases are designed for easy X-ray access.

US DOT Rules: No Extra Fees on US Airlines

The US Department of Transportation requires that US airlines allow passengers to bring CPAP machines without charging additional fees. Under the Air Carrier Access Act and DOT disability rules, airlines cannot:

• Charge a fee for the CPAP as an additional carry-on item
• Count the CPAP against your carry-on allowance
• Refuse to allow you to bring a CPAP on board

This applies to all US-operated flights. If an airline tries to charge you for your CPAP, you can cite DOT's medical device rules and request supervisor assistance. Keep documentation of your machine (model number, a letter from your doctor) to smooth any disputes.

UK and EU Airlines

CPAP machines are medical devices under UK and EU aviation regulations as well, and airlines cannot unreasonably refuse to allow them. However, the specific rules on bag allowance counting and fees vary by carrier.

Before flying on a non-US airline: Contact the airline directly to confirm their CPAP policy. Most major European carriers (Lufthansa, British Airways, Air France, KLM) accommodate CPAP machines without issue. Budget carriers may have less consistent policies — verify in writing before travel.

Distilled Water: Exempt from the 100ml Rule

If you use the CPAP humidifier, you need distilled water. TSA provides a medical liquids exemption:

• Distilled water for CPAP use is exempt from the 100ml (3.4 oz) liquid rule
• Declare it at security when you reach the checkpoint: tell the officer you have CPAP water
• The water should be in a clearly labelled container, separate from your other liquids
• TSA may open and test the liquid — this is routine

Bring enough distilled water for the first night at your destination. Distilled water is available internationally at pharmacies, supermarkets, and sometimes hotel front desks.

Using Your CPAP During the Flight

Most airlines allow CPAP use during flight. The practical considerations:

Seat power: Many aircraft seats now have AC outlets or USB-C power. Check your specific aircraft and seat assignment. An aisle seat is usually preferable because cord management is easier — you can route the hose and power cord without climbing over people.

CPAP battery packs: If your aircraft does not have seat power, or if you prefer not to rely on it, a CPAP travel battery allows cordless operation. Key points:

• Battery capacity is measured in watt-hours (Wh)
• Lithium-ion batteries between 100-160 Wh require airline approval before flight
• Batteries above 160 Wh are prohibited in carry-on by FAA rules
• Many CPAP manufacturers sell FAA-approved travel batteries specifically sized for aircraft use — check your machine's manufacturer
• Carry the battery in carry-on, not checked luggage (lithium battery rule)

Advance notice: Notify the airline when you book that you will be using a CPAP during flight. Many airlines have a process for logging this to avoid any confusion at the gate or on board.

International Use: Power and Water

Dual voltage: Most modern CPAP machines are dual-voltage (100-240V, 50/60Hz). Check the label on the back or bottom of your machine. If it says 100-240V, you need only a plug adapter, not a voltage converter.

Plug adapters: Bring the correct adapter for your destination country. The US uses Type A/B plugs; the UK uses Type G; Europe uses Type C/E/F; Australia uses Type I.

Distilled water internationally: Available at pharmacies (ask for "distilled water" or "acqua distillata" / "agua destilada" etc.). Some hotels in destinations popular with medical tourists keep it on request.

Altitude mode: If you are flying to high-altitude destinations (above 2,000 meters), check whether your CPAP has an altitude adjustment setting. Some machines need manual adjustment for reduced air pressure at altitude.

Documentation

No documentation is legally required in the US for domestic travel with a CPAP. However, carrying the following makes any security or airline interaction smoother:

• Prescription or doctor's letter: A brief letter on letterhead stating you use a CPAP for medically diagnosed sleep apnea, with your doctor's contact information
• Machine information card: Some CPAP manufacturers provide a card listing the model and explaining that it is a medical device
• Insurance or purchase documentation: Useful for customs purposes when traveling internationally with an expensive machine

For international travel, a doctor's letter is strongly recommended. Some foreign security checkpoints are less familiar with CPAP equipment than US TSA officers.

Summary

CPAP travel question	Answer
Allowed in carry-on	Yes
Counts as carry-on bag	No — exempt as medical device
US airlines can charge fee	No — prohibited by DOT rules
Distilled water through security	Yes — exempt from 100ml rule; declare it
Use during flight	Usually yes — check your airline
Battery packs allowed	Yes, under 100 Wh freely; 100-160 Wh with airline approval; above 160 Wh prohibited
Works internationally	Yes — most machines are dual-voltage; bring plug adapter