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This page describes products and general use; it is not medical advice.
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A pressure relief mattress is a mattress made to spread body weight and avoid excess pressure on any one body area, intended, in the FDA regulations, for preventing or treating pressure injuries (bed sores). Staff and buyers who meet the term usually need to know which product family is meant and how the US FDA regulates it. The table below maps each family to its FDA product code, regulation and class.
What is a pressure relief mattress?
The FDA does not use the phrase “pressure relief mattress” as a device name. Its regulation 21 CFR 880.5150 describes a “nonpowered flotation therapy mattress” as a mattress intended for medical purposes that contains air, fluid, or similar materials to support a patient and avoid excess pressure on body areas. The regulation states it is intended to treat or prevent decubitus ulcers (bed sores). In practice, “pressure relief” is an umbrella term for several mattress families that differ in whether they need power.
Who uses it: hospitals, long-term care and home-care providers, and the clinicians and buyers who specify equipment for them.
How the types are built
Nonpowered flotation mattresses (air, fluid or similar fill)
Under 21 CFR 880.5150 the support comes from air, fluid or similar materials inside the mattress, with no control unit. A static air mattress fits this wording only as an air-filled, nonpowered mattress; the regulation does not define it further.
Alternating pressure air flotation mattresses
21 CFR 880.5550 describes multiple air cells that are filled and emptied in an alternating pattern by an associated control unit, so body-pressure distribution changes automatically at regular intervals. It is used to prevent and treat decubitus ulcers. For the comparison with low air loss, see alternating pressure vs low air loss mattresses.
Temperature regulated water mattresses
21 CFR 880.5560 describes a water-filled mattress of suitable size whose water can be heated or, in some cases, cooled. It includes electrical heating and water-circulating components, optional cooling, and manual or automatic temperature control. The regulation does not state a pressure-ulcer purpose, so a “water mattress” is not automatically a pressure relief product.
Types and FDA class
| Family | FDA product code | Regulation | Class | 510(k) |
|---|---|---|---|---|
| Nonpowered flotation therapy mattress | IKY | 21 CFR 880.5150 | I (general controls) | Exempt, subject to 880.9 |
| Alternating pressure air flotation mattress | FNM | 21 CFR 880.5550 | II (special controls) | Exempt, subject to 880.9 |
| Temperature regulated water mattress | FOH | 21 CFR 880.5560 | I (general controls) | Exempt, subject to 880.9 |
Source: the text of each regulation section and the openFDA classification database, listed under Sources (checked 2026-10-30). Under 880.5150, the device is also exempt from the quality management system regulation (part 820) except records and complaint files (820.35). A device class describes regulatory controls, not how well a mattress performs for a given patient.
How to choose
The FDA regulations describe classification, not selection criteria, so this page does not rank products. Two facts follow directly from them: a powered alternating pressure mattress sits in a higher FDA class (II) than a nonpowered flotation mattress (I), and a temperature regulated water mattress is a separate regulatory category. For Medicare coverage groups for support surfaces, see hospital bed mattresses, which cites the CMS policies for Group 1, 2 and 3 surfaces. The clinical choice belongs to the treating clinician and the manufacturer’s instructions for use.
Safe use and handling basics
- Follow the manufacturer’s instructions for use for set-up, power supply and cleaning.
- A mattress cover is part of the system: see vinyl mattress covers.
- A mattress is one part of a wider approach; see pressure injury prevention programmes and what a hospital bed is.
Common mistakes
- Treating “pressure relief” as one product category. The FDA regulations above separate nonpowered, alternating pressure and water mattresses.
- Assuming any water mattress is for pressure injuries. 21 CFR 880.5560 describes a temperature regulated mattress and states no such purpose.
- Reading a lower or higher class as a quality ranking. Class reflects the level of regulatory control.
FAQ
Is a pressure relief mattress the same as an alternating pressure mattress?
No. An alternating pressure air flotation mattress (21 CFR 880.5550, class II) is one kind of pressure relief mattress. It uses a control unit to inflate and deflate air cells in an alternating pattern; a nonpowered flotation mattress (880.5150, class I) has no such unit.
Is a water mattress a pressure relief mattress?
Not by definition. The FDA describes a temperature regulated water mattress (880.5560) by its water-heating and circulating parts and does not state a pressure-ulcer purpose. A nonpowered mattress filled with fluid can fall under 880.5150, which does name preventing or treating decubitus ulcers.
What is a static air mattress?
Under the FDA wording, an air-filled, nonpowered mattress that supports the patient and avoids excess pressure on body areas falls under 880.5150. The regulation does not give a separate definition of “static air”.
Where do low air loss mattresses fit?
See the comparison of alternating pressure and low air loss mattresses.
Sources
- 21 CFR 880.5150, Nonpowered flotation therapy mattress, https://www.law.cornell.edu/cfr/text/21/880.5150 (checked 2026-10-30)
- 21 CFR 880.5550, Alternating pressure air flotation mattress, https://www.law.cornell.edu/cfr/text/21/880.5550 (checked 2026-10-30)
- 21 CFR 880.5560, Temperature regulated water mattress, https://www.law.cornell.edu/cfr/text/21/880.5560 (checked 2026-10-30)
- openFDA device classification, product codes IKY, FNM, FOH, https://api.fda.gov/device/classification.json (checked 2026-10-30)
