Oxygen Therapy

The following requirements are set forth by Medicare. Other requirements and/or guidelines may be necessary to follow. Please call our store, or your physician for further details.

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Home Oxygen Therapy Coverage Criteria

Home oxygen is covered only when both the reasonable and necessary criteria discussed below and the statutory criteria discussed in the Policy Article are met. Refer to the Policy Article for additional information on statutory payment policy requirements.

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Reasonable and Necessary Conditions for Home Oxygen Therapy

Home oxygen therapy is reasonable and necessary only if all of the following conditions are met:

1. The treating physician has determined that the beneficiary has a severe lung disease or hypoxia-related symptoms that might be expected to improve with oxygen therapy, and
2. The beneficiary's blood gas study meets the criteria stated below, and
3. The qualifying blood gas study was performed by a physician or by a qualified provider or supplier of laboratory services, and
4. The qualifying blood gas study was obtained under the following conditions:
   • If the qualifying blood gas study is performed during an inpatient hospital stay, the reported test must be the one obtained closest to, but no earlier than 2 days prior to the hospital discharge date, or
   • If the qualifying blood gas study is not performed during an inpatient hospital stay, the reported test must be performed while the beneficiary is in a chronic stable state (i.e., not during a period of acute illness or an exacerbation of their underlying disease), and
5. Alternative treatment measures have been tried or considered and deemed clinically ineffective.

In this policy, the term “blood gas study” refers to either an oximetry test or an arterial blood gas test.

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Group I Criteria

Group I criteria include any of the following:

• An arterial PO₂ at or below 55 mm Hg or an arterial oxygen saturation at or below 88 percent taken at rest (awake), or
• An arterial PO₂ at or below 55 mm Hg, or an arterial oxygen saturation at or below 88 percent, for at least 5 minutes taken during sleep for a beneficiary who demonstrates an arterial PO₂ at or above 56 mm Hg or an arterial oxygen saturation at or above 89 percent while awake, or
• A decrease in arterial PO₂ more than 10 mm Hg, or a decrease in arterial oxygen saturation more than 5 percent from baseline saturation, for at least 5 minutes taken during sleep, associated with symptoms or signs reasonably attributable to hypoxemia, or
• An arterial PO₂ at or below 55 mm Hg or an arterial oxygen saturation at or below 88 percent, taken during exercise for a beneficiary who demonstrates an arterial PO₂ at or above 56 mm Hg or an arterial oxygen saturation at or above 89 percent during the day while at rest. In this case, oxygen is provided during exercise if it is documented that the use of oxygen improves the hypoxemia demonstrated during exercise when the beneficiary was breathing room air.

Initial Coverage: Beneficiaries meeting Group I criteria are covered for 12 months or the physician-specified length of need, whichever is shorter.

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Group II Criteria

Group II criteria include the presence of:

• An arterial PO₂ of 56-59 mm Hg or an arterial blood oxygen saturation of 89 percent at rest (awake), during sleep for at least 5 minutes, or during exercise (as described under Group I criteria), and
• Any of the following:
  • Dependent edema suggesting congestive heart failure, or
  • Pulmonary hypertension or cor pulmonale, determined by measurement of pulmonary artery pressure, gated blood pool scan, echocardiogram, or "P" pulmonale on EKG, or
  • Erythrocythemia with a hematocrit greater than 56 percent.

Initial Coverage: Beneficiaries meeting Group II criteria are covered for 3 months or the physician-specified length of need, whichever is shorter.

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Group III Criteria

Group III includes beneficiaries with arterial PO₂ levels at or above 60 mm Hg or arterial blood oxygen saturations at or above 90 percent. For these beneficiaries, there is a rebuttable presumption of non-coverage.

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Testing Specifications:

General

For purposes of this policy:

• “Blood gas study” refers to both arterial blood gas (ABG) studies and pulse oximetry.
• “Oximetry” refers to routine or “spot” pulse oximetry.
• “Overnight oximetry” refers to stand-alone pulse oximetry continuously recorded overnight. It does not include oximetry results done as part of other overnight testing such as polysomnography or home sleep testing.

Refer to the Positive Airway Pressure Devices used for the Treatment of Obstructive Sleep Apnea policy for information on sleep tests used for the diagnosis of sleep apnea.

The qualifying blood gas study must comply with the standards set by the Fiscal Intermediary, Local Carrier, or A/B Medicare Administrative Contractor (MAC) and be covered under Medicare Part A or Part B. The test must be performed by a qualified provider, such as a Part A provider, laboratory, Independent Diagnostic Testing Facility (IDTF), or physician. A supplier is not a qualified provider, and blood gas studies performed by a supplier are not acceptable. Furthermore, blood gas studies cannot be paid for by a supplier, except for tests performed by a hospital certified to conduct such tests.

A qualifying blood gas study may be performed while the beneficiary is on oxygen, provided the blood gas values meet the Group I or Group II criteria.

When both arterial blood gas (ABG) and oximetry tests are performed on the same day under the same conditions (e.g., at rest/awake, during exercise, or during sleep), the ABG result will be used to determine whether coverage criteria are met. If an ABG test done at rest and awake is non-qualifying, but an exercise or sleep oximetry test on the same day qualifies, the oximetry test result will be used for coverage determination.

All oxygen qualification testing must be performed in-person by a physician or other qualified medical professional. With the exception of overnight oximetry (see below), unsupervised or remotely supervised home testing does not qualify for Medicare reimbursement of home oxygen and oxygen equipment.

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Exercise Testing

When oxygen is covered based on an oximetry study obtained during exercise, the beneficiary's medical record must document three (3) oximetry studies:

1. Testing at rest without oxygen.
2. Testing during exercise without oxygen.
3. Testing during exercise with oxygen applied to demonstrate improvement of hypoxemia.

All three tests must be conducted within the same testing session, and must be performed in-person by a qualified medical professional. Unsupervised or remotely supervised home exercise testing does not qualify. Only the results from testing during exercise without oxygen are used for qualification and reported on the Certificate of Medical Necessity (CMN). The other two results do not need to be routinely submitted but must be available upon request.

Oximetry obtained after exercise while resting, sometimes referred to as “recovery” testing, is not valid for determining eligibility for oxygen coverage.

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Overnight Oximetry Studies

Overnight sleep oximetry can be performed in a facility or at home. For home overnight oximetry studies, the oximeter provided must be tamper-proof and able to download data that documents the duration of oxygen desaturation below a specified value.

For overnight oximetry studies, the 5 minutes of desaturation do not have to be continuous. Baseline saturation is defined as the mean saturation level during the test. For Group I criteria, a minimum of 2 hours of recorded sleep time is required, with results showing qualifying test values; otherwise, the Group III presumption of non-coverage applies.

Home overnight oximetry is limited to stand-alone pulse oximetry performed under the following conditions:

1. The beneficiary’s treating physician orders the overnight oximetry test from a Medicare-enrolled Independent Diagnostic Testing Facility (IDTF) before the test is performed.
2. The test is performed under the direction and instruction of the IDTF, with clear written instructions for the beneficiary on how to operate the test equipment. The DME supplier may deliver the test unit but cannot participate in the administration or instruction of the test.
3. The test unit must be sealed and tamper-proof, with results accessed only by the IDTF, which will send the test report to the treating physician.

Oximetry test results from the beneficiary’s home, obtained while the beneficiary is awake (either at rest or with exercise), are not valid for home oxygen therapy qualification.

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Obstructive Sleep Apnea (OSA), Polysomnography, and Home Sleep Tests

Some beneficiaries may require the simultaneous use of home oxygen therapy with a Positive Airway Pressure (PAP) device. For simultaneous coverage, both the Oxygen and Oxygen Equipment and PAP Devices for the Treatment of Obstructive Sleep Apnea coverage requirements must be met. This means that the OSA must be sufficiently treated before oxygen saturation results obtained during sleep testing are considered qualifying for oxygen therapy.

For beneficiaries with OSA, a qualifying oxygen saturation test may only occur during a titration polysomnographic study (either split night or stand-alone) where all the following criteria are met:

1. The titration is conducted over a minimum of 2 hours.
2. During titration:
   • The AHI/RDI is reduced to ≤ 10 events/hour, or
   • If the initial AHI/RDI was < 10 events/hour, further reduction is demonstrated.
3. Nocturnal oximetry is performed after optimal PAP settings are determined.
4. The nocturnal oximetry shows oxygen saturation ≤ 88% for 5 minutes total (not necessarily continuous).

If all the above criteria are met, the beneficiary is considered to be in the “chronic stable state” and may qualify for home oxygen therapy. Beneficiaries that qualify based solely on sleep testing are eligible only for reimbursement of stationary equipment.

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Certification:

An Initial, Recertification, or Revised CMN must be obtained and submitted in the situations described below. The Initial Date, Recertification Date, and Revised Date specified below refer to the dates reported in Section A of the CMN.

Initial CMN is required:

• With the first claim for home oxygen (even if the beneficiary was on oxygen prior to Medicare eligibility or oxygen was initially covered by a Medicare HMO).
• During the first 36 months of the rental period, when there has been a change in the beneficiary’s condition that has caused a break in medical necessity of at least 60 days plus whatever days remain in the rental month during which the need for oxygen ended. Refer to the Policy Article NON-MEDICAL NECESSITY COVERAGE AND PAYMENT RULES for additional information.
• When the equipment is replaced because the reasonable useful lifetime of prior equipment has been reached.
• When the equipment is replaced because of irreparable damage, theft, or loss of the originally dispensed equipment.
  • Irreparable damage refers to a specific accident or to a natural disaster (e.g., fire, flood).
  • Irreparable damage does not refer to wear and tear over time.

Testing and Visit Requirements:

Initial Certification (CMN) for Oxygen Therapy:

1. Blood Gas Study Requirements:
   • The blood gas study must be the most recent test obtained within 30 days prior to the initial certification (CMN).
   • Exception: For beneficiaries transitioning from a Medicare HMO, the test must be the most recent qualifying study performed while in the HMO, and the 30-day rule is not required.
2. Physician Visit:
   • The beneficiary must have an evaluation by the treating physician within 30 days prior to the initial certification.
3. Replacement Equipment (Scenarios 3 and 4):
   • Blood gas retesting is not required. The most recent qualifying test value may be used, even if it predates the 30-day rule.

Recertification CMN Requirements:

1. Timing:
   • For Group I patients, recertification is required after 12 months of therapy.
   • For Group II patients, recertification is required after 3 months of therapy.
2. Blood Gas Study:
   • For Group I, the most recent blood gas study before the 13th month must be used.
   • For Group II, the study must be performed between the 61st and 90th day of therapy. A later qualifying test can restart coverage.
3. Physician Visit:
   • Beneficiaries must have a physician evaluation within 90 days prior to recertification.
4. Replacement Equipment:
   • No retesting or physician visits are required for replacement equipment recertifications.

Revised Certification (CMN) Scenarios:

1. Changes Requiring Revised CMN:
   • Changes in oxygen flow rates, length of need, or addition of new equipment require a revised CMN.
2. Testing and Visit Requirements:
   • Some situations require a new blood gas study (e.g., flow rate changes), but no physician visit is required for revised certifications.

Portable Oxygen Systems:

• Covered if the beneficiary is mobile and the qualifying study was performed while awake or during exercise. Portable systems are not covered if the only qualifying test was during sleep.

Liter Flow Greater than 4 LPM:

• A higher allowance for flow rates over 4 LPM requires a qualifying blood gas study with the beneficiary on 4+ LPM.

Miscellaneous:

• Oxygen is reimbursed as a bundled service. Accessories and options are included in the rental payment.
• Stand-by oxygen systems and topical oxygen chambers will not be covered as they are deemed unnecessary.

Refills of Oxygen Contents:

• Billing for refills must be based on prospective usage, and oxygen contents are reimbursed with a monthly allowance.

The above information is provided based on the current understanding and is believed to be accurate, but not guaranteed.

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