Clinicians → Coverage & Documentation · Last reviewed August 17, 2026
How to Qualify a Patient for Home Oxygen
A plain-English guide to Medicare's coverage criteria and documentation requirements for home oxygen therapy — what test the patient needs, what has to be in the chart, and what we need from your office. Based on LCD L33797, Policy Article A52514, and SDR A55426.
For most patients, Medicare needs three things:
- A qualifying oxygen test — usually SpO₂ 88% or lower on room air, at rest and awake.
- A chart note from the treating practitioner — most recent visit or discharge summary with diagnosis, showing the practitioner reviewed the result and determined home oxygen will help.
- A Standard Written Order (SWO) — 6 required elements. We will prepare it for you and send it for signature.
Send those to us and we take it from there — delivery, setup, patient education, and billing.
The patient tested at 89% or higher because they were sitting still and already on oxygen from the hospital. If the patient is short of breath with activity, do the walk test instead — it is the most common way patients qualify, and it is easy to do in the office.
Step 1 — The qualifying test
Everything hinges on a blood gas study — either pulse oximetry (SpO₂) or arterial blood gas (ABG). More than 90% qualify on pulse oximetry.
Timing: at the time of need
Test must be during the illness episode that creates the need — not months earlier. For hospital discharges, qualifying test must be within 2 days of discharge. A day-1 sat on a 5-day admission will not support the claim.
Testing on oxygen is allowed
If the reported value still meets criteria (e.g. ≤ 88% even on oxygen). A patient at 95% on 2 LPM has not qualified. Room-air value is always cleanest.
Who may perform the test
- Treating practitioner (in person)
- Hospital / Part A provider
- Certified laboratory
- IDTF (Independent Diagnostic Testing Facility)
- DME supplier — including us
- Anyone paid by a supplier
- Patient at home with store-bought oximeter
- Remote/telehealth-supervised home test
Testing must be in person — except stand-alone overnight oximetry self-administered at home under IDTF direction (see nocturnal). We cannot perform, pay for, or instruct the test.
Chart note tip: if pigmentation, altitude, age, or oxygen-carrying capacity could affect reliability, describe it in one sentence.
Step 2 — The medical record
We cannot bill from an order alone. The chart must show:
- Qualifying test result — value, date, and conditions (rest/exercise/sleep, room air or on O₂ at __ LPM)
- Practitioner's evaluation of that result — not just a flowsheet number
- Diagnosis driving the hypoxemia — COPD, ILD, fibrosis, HF, PH, lung cancer, etc.
- Home oxygen expected to improve the condition
Most recent visit or discharge summary usually covers all four. Send the whole note — we'd rather read too much than call back.
Step 3 — The Standard Written Order (SWO)
We must have a complete, signed SWO before we submit a claim. Six elements:
- Patient name or MBI
- Order date
- Description of item (narrative or HCPCS)
- Quantity, if applicable
- Treating practitioner name or NPI
- Practitioner signature
- Liter flow — separate day/night if different
- Frequency — continuous / nocturnal / exertion only
- Delivery method — concentrator / POC / cylinders
- Length of need
We will build it for you. Send chart note + test and we'll prepare the SWO for signature. Fax to (800) 438-2048.
Some items are on CMS's Required Face-to-Face + Written Order Prior to Delivery list — signed order must be in hand before the truck rolls. If urgent, call (800) 977-3002 and we'll tell you exactly what must be signed.
The exercise (walk) test
How a large share of patients qualify — those who look fine seated and desaturate when they move. Takes ~10 minutes in a hallway.
Three readings, one session — all in person, same testing session
At rest, room air
Baseline — shows they didn't already qualify at rest
During exercise, room air
Qualifying ≤ 88%
During exercise, on O₂
Proves O₂ corrects it — must be while still walking
Patient walks, desaturates to 85%, goes back on oxygen, everyone is satisfied — and no one writes down the improved number on oxygen. Without proof the sat came back up while still walking on oxygen, the file is incomplete — even though only reading #2 qualifies. A “recovery” sat while sitting after the walk does not count.
How to run it
- Seat patient, let settle, record room-air SpO₂ at rest.
- Walk at comfortable pace — hallway loop or 6-minute walk. Keep probe on.
- Record lowest sustained SpO₂ on room air during ambulation.
- Without stopping, apply oxygen at intended flow and let stabilize.
- Record saturation while still walking on oxygen.
- Document all three values, date, flow used in step 5, and who performed it.
Qualifies for portable oxygen for awake/active use — not automatically continuous/nighttime.
Nocturnal (nighttime-only) qualification
- ≥ 2 hours recorded sleep, qualifying value must be reached during recording.
- Baseline = mean saturation across test (matters for >5% drop criterion).
- Oximeter must be tamper-proof and downloadable (time below threshold).
Two limits: Only stand-alone overnight oximetry counts (not from PSG/home sleep apnea test). Sleep-only qualification = stationary equipment only, no portable. Awake exercise testing cannot be done via home self-test.
Patients with sleep apnea
Oxygen and PAP can be covered together, but treat the apnea first. Desaturation from untreated OSA is an apnea problem, not an oxygen problem. Qualifying saturation must come from a titration polysomnogram meeting:
- Titration runs ≥ 2 hours.
- AHI/RDI brought to average ≤ 10 events/hour (or further reduced if started <10).
- Oximetry recorded only after optimal PAP settings established while on those settings.
- Recorded saturation ≤ 88%.
Must also meet every other oxygen criterion; PAP criteria are separate. Results in stationary equipment only.
Group II — the borderline patient (89% or 56–59 mmHg)
Just above Group I threshold — can still qualify with one second finding documented in the chart:
- Dependent edema suggesting CHF
- Pulmonary hypertension or cor pulmonale — by PA pressure, gated blood pool scan, echo, or P pulmonale on EKG (P > 3mm in II, III, aVF)
- Erythrocythemia — hematocrit > 56%
1. Repeat qualifying blood gas study, evaluated/documented by treating practitioner, and 2. New SWO. Miss that window and payment stops. We track these dates and will reach out in advance — but the visit and retest must happen on your side.
Group III — normoxemic patients
Small number of patients with normal oxygen levels where peer-reviewed literature shows oxygen improves the condition. CMS names cluster headache as an example.
Also requires repeat normoxemic test + new SWO between days 61–90.
What does not qualify
Denied by Medicare
- Angina without hypoxemia
- Dyspnea without cor pulmonale or hypoxemia
- Severe PVD with limb desaturation, no systemic hypoxemia
- Terminal illness not affecting breathing
Not covered
- Standby/emergency oxygen (not regularly used)
- Purchased oxygen equipment (rental only)
- Home pulse oximeters/probes
- Topical oxygen / hyperbaric chambers
- RT services under DME benefit
- Oxygen furnished by airline / outside US
A patient who doesn't meet criteria can still get oxygen cash-pay with an ABN — or purchase a portable concentrator via our retail store →
Which equipment the patient gets
Keeping coverage in place
What happens after we deliver
How Medicare pays for oxygen — different from most equipment:
- 36 rental payments, then it keeps working — we continue to provide equipment, supplies, maintenance, and repairs at no additional rental charge for the balance of the 5-year reasonable useful lifetime.
- Everything bundled — cannulas, tubing, humidifiers, masks, regulators, carts, delivery, back-up, service, and repair included in monthly rental — nothing separately billable.
- 5-year reasonable useful lifetime — starts at initial date of service, not manufacture; not reset by swap/modality/supplier change. At 5 years, patient may elect new equipment (fresh 36-month cycle). Stationary + portable replaced together.
- Changing suppliers does not restart — new 36 months only for damage beyond repair / lost / stolen, or genuine break in need >60 days + remainder of month with new medical necessity.
- Hospital/SNF stays — if patient still needs oxygen on return, billing resumes where left off, no new qualifying test.
- Travel — we remain responsible when they travel or relocate; call before trip — arrangements differ for 2-week visit vs permanent move, Medicare pays one supplier per month.
Referral checklist
Fax to (800) 438-2048 or call (800) 977-3002
- Qualifying test result — value, date, rest / exercise / sleep, room air or on O₂ at __ LPM
- If exercise: all three readings, including walking-on-oxygen value
- Most recent chart note showing practitioner evaluated the result
- Pulmonary or cardiac diagnosis
- Standard Written Order, signed — or tell us and we'll draft it
- Liter flow, frequency, and delivery method
- Patient demographics and insurance
- Notes on reading reliability (pigmentation, altitude, age) if relevant
Sources: Medicare LCD L33797 — Oxygen and Oxygen Equipment; Policy Article A52514; Standard Documentation Requirements A55426; NCD 240.2. Last reviewed August 17, 2026.
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