HCPCS A7037: Tubing for positive airway pressure device

Know what documentation and billing requirements you need to meet to properly use and bill for HCPCS code A7037, in our short guide.

Use Code

## **What is HCPCS code A7037?** HCPCS code A7037, which has a service type of “Durable Medical Equipment (DME) / Medical and Surgical Supplies (specifically breathing aids),” has a full description of “Tubing used with positive airway pressure device.” The equipment described by this code refers to specialized tubing used in delivering continuous or bilevel positive airway pressure (PAP) therapy. This tubing connects a PAP device—such as CPAP or BiPAP—to the patient’s mask, nasal cannula, or interface, forming a crucial component of the therapy circuit. Though not a procedure, the tubing is an essential supply item categorized under breathing aids. The primary role of CPAP or BiPAP tubing is to transport pressurized air, helping to maintain airway patency in patients with obstructive or central sleep apnea. Effective PAP therapy reduces apnea–hypopnea events, relieves excessive daytime sleepiness, improves oxygenation, and ultimately helps patients improve sleep quality. This code is primarily used to bill for the replacement of standard PAP tubing when the base PAP device (e.g., E0601) is deemed medically necessary under the applicable Local Coverage Determinations (LCDs). Continued coverage typically requires documentation of ongoing use of PAP therapy and, for supply replacements, a documented refill request from the beneficiary or caregiver confirming the need for new tubing.

## **HCPCS code A7037 documentation requirements** Accurate and thorough documentation is essential for coverage and reimbursement of PAP accessories like A7037. Key documentation includes: - **Standard Written Order (SWO)**: A written prescription or order from the treating practitioner (e.g., physician, nurse practitioner) is required for both the initial PAP device and for replacement accessories. The order must specify the item (A7037), the quantity, and the frequency of replacement (e.g., "1 per 3 months"). - **Medical necessity**: There must be documentation in the patient's medical record to support the medical necessity of the base PAP device (E0601 or similar), usually a diagnostic sleep study confirming a diagnosis like Obstructive Sleep Apnea (OSA). For replacements, the medical record must support the continued need and use of the PAP therapy. - **Replacement schedule documentation**: Centers for Medicare and Medicaid Services (CMS) and other payers set guidelines for the maximum allowable replacement frequency. For A7037 (standard tubing), the typical replacement schedule is one (1) unit every three (3) months. Billing more frequently than this maximum is likely to result in a denial. The supplier must retain proof of delivery documentation (POD) to confirm the date of delivery and that the items were provided to the beneficiary.

## **A7037 billing requirements** To ensure proper reimbursement for HCPCS code A7037, suppliers must meet the following: - **Frequency limit**: Coverage generally allows one unit of A7037 every three (3) months. Claims submitted more frequently are likely to be denied. - **Modifiers**: Claims should include the appropriate modifiers to confirm compliance with payer policies. For Medicare, the KX modifier is typically required to show that all LCD medical necessity criteria have been met. The NU modifier may also be used by some payers to indicate that the tubing supplied is new. - **Beneficiary-owned equipment narrative**: If billing only for replacement tubing while the patient owns the base PAP device (e.g., E0601), include a note in the claim that specifies the HCPCS code of the device, confirms it is beneficiary-owned, and indicates the approximate month and year of its purchase.

## **Other relevant codes** - **A7036**: Chinstrap used with positive airway pressure device - **A4604**: Heated tubing used with PAP device1 per 3 months - **A7032**: Cushion for use on nasal mask interface, replacement only, each - **A7034**: Nasal interface (mask or cannula type) used with PAP device1 per 3 months - **A7030**: Full face mask used with PAP device1 per 3 months - **A7038**: Filter, disposable, used with PAP device2 per 1 month - **A7039**: Filter, non-disposable, used with PAP device1 per 6 months - **A7035**: Headgear used with PAP device1 per 6 months - **E0471**: Respiratory assist device, bi-level pressure capability, with back-up rate feature, used with noninvasive interface, e.g., nasal or facial mask (intermittent assist device with continuous positive airway pressure device) - **E0601**: Continuous air pressure device (the machine itself)

Frequently asked questions

A7037 is for standard (non-heated) CPAP tubing used with positive airway pressure devices. A4604, on the other hand, is for heated tubing, which is used in conjunction with a humidifier to maintain a set temperature and prevent rainout (condensation) inside the tube. You would typically only bill for one or the other, depending on the type of tubing the patient is prescribed.

Common reasons for denial include billing too frequently, missing KX modifier, lack of valid SWO, and no proof of delivery.

No, for Medicare and most private payers, the maximum allowable replacement schedule for standard tubing (A7037) is one unit every three months. Billing monthly is likely to be denied as being in excess of the statutory replacement schedule.