Travelling With a CPAP Machine: A Complete Guide

Quick answer: what you need to know before you fly

A CPAP machine is legally a medical device, not a piece of luggage: it does not count toward your carry-on or personal item limit (source: U.S. Department of Transportation). It can go through security in its own case for X-ray screening, and liquids for the humidifier are exempt from the standard 3-1-1 rule (source: TSA). It is allowed in carry-on or checked baggage, though carry-on is strongly recommended, and if it runs on a lithium battery, that battery is required to travel in carry-on baggage rather than checked (source: TSA).

Key takeaways

CPAP machines don’t count as a carry-on item under Department of Transportation guidance, as long as the bag carries only the device and its accessories (source: U.S. DOT).
TSA lets your machine stay in its case for X-ray screening in standard lanes, and stay in your carry-on bag too if you have PreCheck (source: TSA).
Humidifier water is exempt from the 3-1-1 liquids rule “in reasonable quantities” (source: TSA).
Lithium batteries must travel in carry-on, not checked baggage, and standard batteries are capped at 100 watt-hours, with up to two spares between 101 and 160 watt-hours allowed with airline approval (source: FAA).
Many modern machines auto-adjust for altitude, typically up to somewhere between 7,500 and 8,500 feet depending on the model, but not every device does — check your manual (source: Philips) (source: ResMed).
Airlines can require up to 48 hours’ advance notice for certain assistive devices, so it is worth telling your airline you are travelling with one (source: U.S. DOT).
TSA Cares can help you plan ahead if you want extra support at the checkpoint (source: TSA).

This guide is written by the CPAP Community editorial team. We are not clinicians or travel agents, so every regulatory claim below is linked to its primary source. Airline-specific policies vary, so confirm anything unusual with your airline directly before you fly.

Is a CPAP machine really a “medical device” for travel purposes

Yes. The Department of Transportation treats a CPAP machine as an assistive device rather than ordinary luggage: it “does not count toward airline baggage limits,” although if your bag also holds personal items unrelated to the device, the airline can count the whole bag toward your limit (source: U.S. DOT). Keep the case dedicated to the machine, mask, tubing and cables, and it should not eat into your carry-on or personal item allowance.

Airlines are required to stow your device in an overhead bin, under the seat in front of you, or another compliant storage area, and to return it to you in the same condition and as close to the aircraft door as possible unless you ask for it at baggage claim instead (source: U.S. DOT). Airlines can also require up to 48 hours’ advance notice for certain assistive devices, so a quick call or note in your reservation ahead of time is a reasonable precaution (source: U.S. DOT).

Getting through security

In a standard screening lane, your CPAP, BiPAP or APAP machine “may remain in their carrying case for X-ray screening, but may be required to be removed from the carry-on,” while masks and tubing can stay in the case throughout (source: TSA). If you have TSA PreCheck, the device can stay in its case and in your carry-on bag for the entire screening (source: TSA). Distilled water and other liquids associated with your humidifier are exempt from the standard 3.4-ounce liquids rule, in reasonable quantities (source: TSA). As with any checkpoint, the final decision on what is allowed through rests with the TSA officer on duty (source: TSA).

If you would like to plan the checkpoint experience ahead of time, TSA Cares coordinates arrangements for travellers with medical devices and conditions, and can be reached before your trip to ask questions or request assistance (source: TSA Cares). A letter from your doctor confirming the equipment is medically necessary is not required, but some travellers find it reassuring to carry one (source: ResMed).

Carry-on or checked bag

TSA permits CPAP equipment in both carry-on and checked baggage (source: TSA), but carry-on is the safer choice: checked bags are handled roughly and occasionally lost, and a CPAP machine is not something you want to be without on the first night of a trip. There is also a hard rule that pushes the decision for you if your device runs on a lithium metal or lithium-ion battery — that battery is required to travel in carry-on baggage, not checked (source: TSA).

In-flight power and battery rules

Whether you can run your CPAP from an aircraft’s own power varies by airline and aircraft, so it is worth checking with your carrier in advance. If you are relying on a portable battery pack instead, standard lithium-ion batteries are limited to 100 watt-hours with no special approval needed, and you may carry up to two spare larger batteries between 101 and 160 watt-hours with airline approval; batteries above that are not permitted (source: FAA). Check the label on your battery pack for its watt-hour rating before you travel, and remember that any device with this kind of battery has to be in your carry-on, never checked (source: FAA).

Adjusting for altitude

Aircraft cabins are pressurised, and many auto-adjusting CPAP and APAP machines compensate for that automatically. Philips states that its DreamStation Go “automatically compensates therapeutic pressure to altitudes of up to 7,500 ft” (source: Philips), while ResMed says most of its devices “automatically compensate for higher altitude changes,” with some lightweight models needing manual adjustment instead (source: ResMed). The specifics vary by model, so check your own device’s manual, or ask your equipment supplier to confirm, particularly if your trip includes a genuinely high-altitude destination rather than just the flight itself.

Water for your humidifier on the road

Manufacturers generally recommend distilled water for CPAP humidifiers to limit mineral buildup in the water chamber and heater plate over time. When you are travelling, pack enough for the trip if you can, or plan where you will buy it once you land — distilled water is sold in most pharmacies and grocery stores in the United States, though availability and labelling can vary abroad. Bottled water is a reasonable backup for a night or two if distilled water is not available, but it is not a long-term substitute. As covered above, water for your humidifier is exempt from TSA’s standard liquid limit, so bringing a travel bottle through security is not an issue (source: TSA).

Power and voltage abroad

Most modern CPAP power supplies are dual-voltage, auto-sensing units built to run on anywhere from about 100 to 240 volts, including the unusual 110-volt, 400-hertz supply used on many aircraft (source: ResMed). Check the label on your specific power brick before you travel: if it lists a range like “100–240V,” you only need a plug shape adapter for the country you are visiting, not a voltage converter. If your supply lists a single voltage, such as 120V only, you will need a proper voltage converter for countries running on 220–240V current, not just a plug adapter — using the wrong one can damage the machine.

A short pre-trip checklist

Confirm your power supply’s voltage range on the label, and pack the right adapter or converter.
Pack a spare filter, cushion or mask cushion and a length of tubing in case something fails away from home.
Check your battery pack’s watt-hour rating if you are bringing one, and keep it in your carry-on.
Plan your distilled water supply, or confirm where you can buy it at your destination.
Tell your airline in advance if you would like extra time or assistance, and check whether they need advance notice for your device.
If it would put you at ease, request TSA Cares assistance or bring a note from your clinician confirming the equipment is medically necessary.

If you are still early in therapy, it is worth reading your first 30 days on CPAP before a big trip — a schedule change and an unfamiliar bed are exactly the kind of disruption that is easier to handle once the habit is already established.

Frequently asked questions about travelling with a CPAP machine

Does a CPAP machine count as a carry-on item?

No. Under Department of Transportation guidance, a CPAP machine does not count toward your airline baggage limits, as long as its case is dedicated to the device and its accessories rather than mixed with personal items.

Can I bring my CPAP humidifier water through airport security?

Yes. TSA exempts liquids associated with CPAP and nebulizer equipment from the standard 3-1-1 liquids rule, in reasonable quantities.

Should I pack my CPAP in a carry-on or checked bag?

TSA allows either, but carry-on is strongly recommended to avoid damage or loss. If your device runs on a lithium battery, that battery is required to travel in carry-on baggage rather than checked.

What are the battery rules for travelling with a CPAP?

Standard lithium-ion batteries up to 100 watt-hours are allowed without special approval. You may carry up to two spare batteries between 101 and 160 watt-hours with airline approval, and batteries above that limit are not permitted. Any lithium battery must travel in carry-on baggage.

Does my CPAP automatically adjust for cabin altitude?

Many modern auto-adjusting CPAP and APAP machines compensate for altitude automatically, with manufacturer-stated ranges commonly around 7,500 to 8,500 feet, but this varies by model and some lightweight or older devices need manual adjustment. Check your specific device's manual to confirm.

Can I use tap water in my CPAP humidifier while travelling?

Manufacturers generally recommend distilled water to limit mineral buildup in the humidifier chamber. If distilled water is not available, bottled water is a reasonable short-term backup, but it is not a substitute for distilled water over the long term.

Do I need a voltage converter for my CPAP when travelling internationally?

It depends on your power supply. If the label on your power brick lists a range such as 100 to 240 volts, you only need a plug shape adapter. If it lists a single voltage, such as 120V only, you need a proper voltage converter for countries running on 220 to 240 volts, since the wrong equipment can damage the machine.

Sources

How we source this guide

This guide is researched and written by the CPAP Community editorial team. We are writers and researchers, not clinicians. Clinical statements are traced to primary sources — the National Heart, Lung, and Blood Institute, the U.S. Food and Drug Administration, the Centers for Medicare & Medicaid Services and the American Academy of Sleep Medicine — and cited in the text so you can check them. We sell no CPAP equipment and take no manufacturer sponsorship. Nothing here is medical advice; see our medical disclaimer and speak to your own sleep clinician before changing your therapy.

Last reviewed by the CPAP Community editorial team: August 2026.

Travelling With a CPAP Machine: TSA, Batteries, Altitude and Power