## Definition
The HCPCS code E1390 refers to “Oxygen concentrator, single delivery port, capable of delivering oxygen at greater than four liters per minute (LPM).” This code is used in medical billing for the rental of a stationary oxygen concentrator that supplies oxygen to patients requiring long-term oxygen therapy. The code E1390 specifically applies to devices that can deliver more than the basic four liters per minute, making it suitable for certain patients with higher oxygen demands.
This code is primarily employed in the outpatient context, where the oxygen concentrator is provided for use in a patient’s home. It is intended for continuous use, meaning the rental of the equipment is generally covered for a period, rather than as a one-time purchase. Given the nature of the equipment, this code often applies to patients with chronic respiratory conditions including chronic obstructive pulmonary disease (COPD) and other disorders that cause hypoxemia.
## Clinical Context
Oxygen therapy is frequently prescribed for patients with conditions that impair their ability to maintain adequate blood oxygen levels. Such conditions include chronic obstructive pulmonary disease, interstitial lung disease, and pulmonary hypertension, among others. These patients often rely on oxygen provided by concentrators like those billed under code E1390 to maintain their oxygen saturation within a therapeutic range.
The decision to prescribe an oxygen concentrator typically follows an arterial blood gas test or pulse oximetry demonstrating the need for supplemental oxygen. Oxygen concentrators deliver air with higher oxygen levels, thus allowing patients with respiratory insufficiencies to live more active and healthier lives. As such, E1390 is essential in documenting long-term, sometimes lifelong, oxygen therapy.
## Common Modifiers
Modifiers are frequently appended to HCPCS code E1390 to communicate additional information about the service provided. A common modifier is the “RR” modifier, which signifies that the equipment is rented rather than purchased. This is crucial, as commercial insurers and Medicare typically cover oxygen concentrators under rental rather than purchase models.
Another frequent modifier is the “KX” modifier, which is used to indicate that the requisite medical justification and documentation, as established by local coverage determinations, have been submitted and verified. It is also possible to see the “GA” or “GZ” modifier, denoting whether an advanced beneficiary notice (ABN) has been issued or not when coverage issues are anticipated.
## Documentation Requirements
Proper documentation is essential for the appropriate billing of HCPCS code E1390. The prescribing physician must provide a detailed prescription that includes the patient’s oxygen flow rate, frequency of use, and certification of the medical necessity of the equipment. Justifications must be based on clinical tests, such as pulse oximetry or arterial blood gas readings demonstrating hypoxemia.
In addition, suppliers must maintain records showing both the medical documentation from the prescribing physician and proof of delivery to the patient. Correct documentation should be maintained to verify the ongoing need for oxygen therapy, including reassessment of the patient’s oxygen requirements on a periodic basis. Non-compliance with documentation requisites may result in denial of reimbursement.
## Common Denial Reasons
Claims for E1390 may be denied for several reasons, often stemming from insufficient or incorrect documentation. A common reason for denial is the failure to provide appropriate medical records demonstrating oxygen desaturation, particularly when test results such as arterial blood gases or pulse oximetry do not meet coverage thresholds. Furthermore, failure to append the “KX” modifier to denote correct documentation of medical necessity may lead to automatic denials.
Another frequent denial occurs when the coverage limits, typically determined by Medicare or commercial payers, are exceeded without appropriate justification for sustained therapy. Claims can also be denied if the patient fails to meet continued documentation requirements demonstrating the ongoing need for oxygen concentrator use.
## Special Considerations for Commercial Insurers
Coverage policies for E1390 can vary significantly between commercial insurers. While Medicare typically provides solid guidelines for coverage, commercial insurers may impose additional prior authorization requirements, or offer rental programs that span different durations before coverage begins. Some insurers may demand time-limited rentals, after which the patient or plan member is required to transition to a purchased model or continues renting under a different code.
In contrast to Medicare’s streamlined coverage rules, commercial insurers may also factor in co-payments, deductibles, or other patient cost-sharing responsibilities differently. Providers must carefully review the specific insurer’s policy to avoid claim denials or underpayment, which may cover not just the rental costs, but also routine maintenance or supplemental accessories required for the concentrator.
## Similar Codes
There are several related codes within the HCPCS system that are used for oxygen delivery equipment, depending on the type of equipment and the flow rate required. HCPCS code E1392 describes a portable oxygen concentrator, which can also be rented but is intended for patient mobility, rather than fixed home use. Code E0431 refers specifically to portable gaseous oxygen systems, which provide oxygen in compressed tank form rather than through a concentrator.
Code E0441 refers to stationary gaseous oxygen systems, which provide oxygen through stored gas cylinders for patients not using a concentrator. Similarly, E0444 refers to a portable liquid oxygen system, an alternative source of oxygen concentrators that provide higher concentrations of oxygen but in liquid form. While these codes pertain to distinct types of oxygen delivery, they are comparable to E1390 in their provision for long-term at-home oxygen therapy.