A fingertip pulse oximeter is the cheapest diagnostic instrument a clinic buys and one of the most consequential. It decides who goes to the emergency department from a nursing station, who qualifies for home oxygen under Medicare, and which respiratory patient gets a second look in a crowded winter waiting room. The 2026 buying question is not price. It is whether the unit on the order is an FDA-cleared medical device, whether its accuracy claim holds across skin tones, and whether the facility's protocol reads the number correctly. Keystone supplies fingertip and pediatric pulse oximeters and probes in the diagnostic instruments line from Edina, Minnesota. Here is what to check before the next order.
Prescription and cleared, or wellness and not
Pulse oximeters are Class II devices under 21 CFR 870.2700, which means a unit sold for medical purposes goes through 510(k) clearance. FDA's 2021 safety communication drew the line buyers still need: prescription oximeters are reviewed by FDA, receive 510(k) clearance and are available with a prescription, while over-the-counter wellness oximeters are not cleared and should not be used for medical purposes. FDA's current consumer page, updated March 2025, adds that a small number of oximeters intended for medical purposes are now available over the counter, and that units sold for sports, aviation or general wellness are not reviewed or evaluated by the agency.
The practical test is the 510(k) number. A cleared device has one, the manufacturer can produce it, and the labeling says "prescription" or states an intended medical use. A unit sold on a marketplace listing with the word "wellness" and no clearance is a consumer gadget, and a facility that documents a clinical decision on its reading has a problem it did not need. Ask for the clearance reference with the quote; Keystone supplies it on request.
The accuracy number on the box
FDA's 2013 guidance, still the operative one for 510(k) submissions, sets the accuracy expectation that cleared devices are tested against: a root-mean-square accuracy, written ARMS, of 3.0 percent or less for transmittance, wrap and clip sensors, and 3.5 percent or less for ear clip and reflectance sensors, measured over an arterial saturation range of 70 to 100 percent. The 2013 testing rule on pigmentation required at least two darkly pigmented subjects or 15 percent of the study pool, whichever was larger.
Two things follow from that number. First, ARMS 2 percent is a better device than ARMS 3 percent and the box will say so; ask. Second, FDA's own safety communication tells clinicians that a pulse oximeter reading of 90 percent may represent an arterial saturation anywhere from 86 to 94 percent, that accuracy is lowest below 80 percent, and that decisions should rest on trends over time rather than a single threshold. Write the protocol that way and train to it.
What the draft guidance changes, and what it does not yet
In January 2025 FDA issued a draft guidance, "Pulse Oximeters for Medical Purposes," that proposes replacing the 2013 testing approach. The draft recommends more clinical study participants, a skin tone distribution measured both by the Monk Skin Tone Scale and by individual typology angle, and, for devices that perform comparably across skin tones, a prominent labeling statement so buyers can identify them. FDA also proposed a public web page listing cleared devices that meet the new performance recommendations. Trade reporting on the draft describes a study population of 150 or more participants spread across three skin tone groups, with at least a quarter in each group, up from a minimum of 10 subjects in the old approach.
As of late October 2026 it is still a draft. FDA's guidance page labels it "not for implementation," and the agency's pulse oximeter page says it will supersede the 2013 guidance once finalized. That is the status to buy against. A device cleared in 2026 was cleared under the 2013 rules unless the manufacturer chose to test to the draft, and some have. If a vendor claims comparable performance across skin tones, ask for the study summary and the ARMS by group. If the vendor cannot produce it, the claim is marketing.
The history matters for a buyer who has to explain the purchase to a medical director. FDA's advisory panel took the issue up on November 1, 2022, FDA published a discussion paper on skin pigmentation in November 2023, the panel met again on February 2, 2024, and the draft followed in January 2025. A Johns Hopkins review published in December 2024 looked at 767 oximeter clearance summaries from 1996 to 2024 and found the 2013 pigmentation recommendation was rarely followed. The direction is set. The final rule is not.
Where the reading decides money and care
Medicare's National Coverage Determination 240.2 for home oxygen uses an arterial oxygen saturation at or below 88 percent, taken at rest and breathing room air, as the qualifying Group I measurement, and 89 percent with supporting findings for Group II. A pulse oximeter is how that number is usually taken in a clinic or at a bedside in senior living. A device with a 3 percent ARMS can put a patient on either side of 88. That is the strongest argument for buying the better device, keeping it calibrated, and recording the probe, the site and the patient's condition with every reading.
The order list by setting
| Setting | What to buy | Why |
|---|---|---|
| Primary care and urgent care | Fingertip units, cleared, ARMS 2 to 3 percent, one per exam room plus two spares | Vitals at every visit, respiratory season volume |
| Senior living nursing stations | Fingertip units plus one handheld with adult and pediatric probes | Residents with poor perfusion and cold hands read better on a handheld |
| EMS and public safety | Handheld or monitor-integrated units with disposable probes | Field durability, infection control between patients |
| School and employer health offices | Cleared fingertip units, not consumer wellness devices | The reading may send someone to the ED |
| Home health and remote monitoring | Cleared fingertip units supplied to patients, with written reading instructions | Trend-based protocols need consistent devices |
Buy spares and batteries with the units, and put probe covers and alcohol prep pads on the same order. A cleared device with a dead battery is a wellness device.
Three mistakes to stop making
- Buying by price on a marketplace. The listings that sell for a third of the price are the ones without a 510(k). The savings disappear on the first reading that drives a wrong decision.
- Treating 88 as a switch. FDA says to read trends. A protocol that acts on a single number from a cold finger in a hallway is not using the device the way its clearance assumes.
- Ignoring pigmentation in the protocol. The draft guidance is not final, but the safety communication has said since 2021 that skin pigmentation affects accuracy. Where a reading is borderline, confirm with a second reading, a different site, or an arterial blood gas where the setting allows it.
How Keystone supplies them
Keystone supplies FDA-cleared fingertip and pediatric pulse oximeters from American Diagnostic Corporation, along with probes, probe covers and batteries, to clinics, senior living communities, EMS agencies and public health programs, with the 510(k) reference and the manufacturer's accuracy specification available on request. Case and multi-site pricing is quoted the same business day during business hours, and approved accounts ship on Net 30. For a group standardizing devices across sites, the method in standardizing blood pressure cuffs and stethoscopes applies to oximeters as well: one model, one probe, one protocol.
Browse diagnostic instruments or request a quote at (320) 808-3686 with your site count, and Keystone will return cleared options with the accuracy numbers side by side.
Sources
- FDA, Draft Guidance: Pulse Oximeters for Medical Purposes, Non-Clinical and Clinical Performance Testing, Labeling, and Premarket Submission Recommendations (January 2025): https://www.fda.gov/regulatory-information/search-fda-guidance-documents/pulse-oximeters-medical-purposes-non-clinical-and-clinical-performance-testing-labeling-and
- FDA press release, FDA Proposes Updated Recommendations to Help Improve Performance of Pulse Oximeters Across Skin Tones (January 6, 2025): https://www.fda.gov/news-events/press-announcements/fda-proposes-updated-recommendations-help-improve-performance-pulse-oximeters-across-skin-tones
- FDA, Pulse Oximeters (device page, current status of the 2013 and draft guidance): https://www.fda.gov/medical-devices/products-and-medical-procedures/pulse-oximeters
- FDA, Pulse Oximeter Basics (consumer update, March 26, 2025): https://www.fda.gov/consumers/consumer-updates/pulse-oximeter-basics
- FDA, Pulse Oximeters, Premarket Notification Submissions [510(k)s], Guidance for Industry and FDA Staff (March 4, 2013): https://www.fda.gov/regulatory-information/search-fda-guidance-documents/pulse-oximeters-premarket-notification-submissions-510ks-guidance-industry-and-food-and-drug
- FDA, Pulse Oximeter Accuracy and Limitations: FDA Safety Communication (February 19, 2021), as reproduced by Healthcare Purchasing News: https://www.hpnonline.com/surgical-critical-care/med-surg-equipment/article/21211195/fda-safety-communication-pulse-oximeter-accuracy-and-limitations
- FDA, CDRH Takes Steps to Advance Further Discussions on Pulse Oximeters (advisory panel and discussion paper history): https://www.fda.gov/medical-devices/medical-devices-news-and-events/cdrh-takes-steps-advance-further-discussions-pulse-oximeters
- 21 CFR 870.2700, Oximeter: https://www.law.cornell.edu/cfr/text/21/870.2700
- CMS, National Coverage Determination 240.2, Home Use of Oxygen: https://www.cms.gov/medicare-coverage-database/view/ncd.aspx?ncdid=169
- Johns Hopkins Bloomberg School of Public Health, Pulse Oximeters Infrequently Tested by Manufacturers on Diverse Sets of Subjects (December 30, 2024 research letter): https://publichealth.jhu.edu/2025/pulse-oximeters-infrequently-tested-by-manufacturers-on-diverse-sets-of-subjects
- Healthcare Dive, FDA draft guidance on pulse oximeter accuracy (January 2025): https://www.healthcaredive.com/news/fda-draft-guidance-pulse-oximeter-accuracy/736646/
