What's in a CPAP Prescription?

Quick answer: A CPAP prescription records your diagnosis, the device type, the pressure mode and settings, the mask type or size, and any humidifier requirement. It is signed and dated by a qualified prescriber. The exact rules vary by country, but a complete prescription should give a supplier enough information to dispense the right equipment without guessing.

Why a prescription exists

CPAP is a medical device that delivers positive pressure to your airway. The wrong pressure or mode can be ineffective or uncomfortable. A prescription connects the diagnosis to the settings, and it gives the supplier a legal and clinical basis for dispensing the equipment.

In the US, a prescription is generally required for a CPAP machine and often for masks and replacement supplies. In other countries, the rules vary: some require a prescription, some require a specialist's order for funding, and some allow over-the-counter purchase of certain devices. Always check locally.

The core fields

• Patient details: name, date of birth and sometimes an address or identifier.
• Diagnosis: obstructive sleep apnea, central sleep apnea or another condition, often with the AHI or severity.
• Device type: CPAP, APAP (auto-adjusting), BiPAP or another mode.
• Pressure settings: a fixed pressure in cmH2O, or an auto range with minimum and maximum.
• Mask: type and size, if specified.
• Humidifier: heated or not, if required.
• Prescriber: name, signature, registration number and date.
• Duration or expiry: how long the prescription is valid, if stated.

A prescription that says only "CPAP" without a pressure or mode is incomplete for most suppliers. Ask for the details.

Pressure settings are not arbitrary

A fixed pressure is usually based on a titration study or a clinician's review of your data. An auto-adjusting range may be set with a minimum and maximum that keep the airway open without causing unnecessary pressure. The range is not a "set it and forget it" default; it should be reviewed.

Do not change the settings on your own. A higher pressure can cause leaks, swallowed air and, in some people, more central events. If you think the settings are wrong, ask for a data review. Our guide to reading your CPAP data explains what the clinician will look at.

Mask and humidifier details

The mask is part of the prescription because fit affects treatment. A supplier may substitute a similar mask, but the prescription should specify the type and size where it matters. If you have a nasal mask, a full-face mask or nasal pillows, the prescription should reflect that.

A humidifier is often optional, but it can make treatment tolerable for people with dryness, congestion or a sensitive airway. Ask whether it is included in the prescription and the funding.

How long is a CPAP prescription valid?

Validity varies. In the US, many prescriptions are written for one to two years, and some suppliers require a renewal before dispensing a new machine or mask. In other countries, a prescription may not have a formal expiry but the clinic may want a review before continuing equipment. Ask your prescriber and supplier what applies to you.

Keep a digital copy and a paper copy. If you travel, move or change suppliers, you will need it.

If you do not have a prescription

Start with the clinician who diagnosed you or your GP. They may be able to issue a replacement or renew an expired one after reviewing your data. If you were diagnosed in another country, the new clinician may need to see the original study before writing a local prescription.

Do not buy a machine from an unregulated seller who offers to "include" a prescription without assessing you. That is not a prescription; it is a workaround.

Your copy matters

Keep a PDF and a paper copy of the prescription with your travel documents. If you use a different supplier, travel with the machine or need emergency replacement parts, the prescription answers the first question a supplier will ask. It also helps if your clinic closes or you move.

Do not edit the document yourself. If a detail is wrong, ask the prescriber to correct and reissue it.

Questions to ask before you fill it

1. Does the prescription specify the device type and mode?
2. Are the pressure settings clear, including the auto range?
3. Is the mask type and size included?
4. Is a humidifier covered?
5. How long is the prescription valid?
6. Can the supplier substitute a different machine or mask?
7. Who do I contact if the settings do not match my machine?

Our guide to getting started with CPAP covers the first weeks of treatment. If you need a clinician to review your prescription, our sleep doctor directory can help.

Frequently Asked Questions

Do I need a prescription to buy a CPAP machine?

In the US, yes, generally for the machine and often for masks and supplies. In other countries, rules vary. Some require a prescription or specialist order for funding; some allow over-the-counter purchase. Check with the supplier and your health system.

What pressure should be on my CPAP prescription?

A fixed pressure in cmH2O, or an auto-adjusting range with a minimum and maximum. The setting should be based on a titration study or a review of your data, not a generic default. Ask your clinician to explain it.

Can a GP write a CPAP prescription?

In many countries, yes, especially if the diagnosis is established and the settings are documented. Some suppliers or funders require a sleep specialist. Ask the supplier what it will accept.

How often does a CPAP prescription need renewing?

It varies. Some prescriptions are valid for one to two years; others have no formal expiry but require periodic review. Ask your prescriber and supplier before your supplies run out.

Can I use my prescription in another country?

Not automatically. Equipment standards, prescription rules and funding differ. Ask the new supplier and clinician whether they will accept it or require a local assessment.

What if my prescription and machine settings do not match?

Do not adjust the machine yourself. Contact the prescriber or supplier and ask them to clarify. A mismatch can mean the wrong mode or pressure, which affects treatment.

This article is general information, not medical advice. It does not replace an assessment by a qualified clinician who can review your history, medications and test results.