Modifier AU- Urological, Ostomy, or Tracheostomy Supply

Modifier AU identifies an item furnished in conjunction with a urological, ostomy, or tracheostomy supply.

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What is Modifier AU?

Modifier AU identifies certain items furnished in conjunction with urological, ostomy, or tracheostomy supplies.

CMS created AU along with AV and AW to distinguish supplies and equipment that can potentially fall under more than one DMEPOS benefit category. The modifier provides additional information allowing Medicare to determine the appropriate benefit and payment treatment for an eligible item.

Modifier AU is therefore not a general modifier for every urological, ostomy, or tracheostomy item. It applies to specific HCPCS items when they are furnished in conjunction with supplies covered under these benefit categories.

Current Medicare coverage policies should always be checked because modifier requirements can depend on both the HCPCS code and the type of supply with which the item is being used.

When to Use Modifier AU

Urological Supplies: Use AU with applicable HCPCS items when they are furnished in conjunction with qualifying urological supplies.

Ostomy Supplies: AU may identify eligible items furnished in connection with covered ostomy supplies.

Tracheostomy Supplies: Applicable items furnished with tracheostomy supplies may require AU under Medicare policy.

HCPCS Code Requires Identification: The underlying supply code must be one for which AU is applicable under the relevant coverage policy.

Documentation Supports the Relationship: Records should demonstrate that the reported item was actually furnished for use with the qualifying urological, ostomy, or tracheostomy supply.

When NOT to Use Modifier AU

Unrelated DMEPOS Item: Do not report AU when the item was not furnished in conjunction with a qualifying urological, ostomy, or tracheostomy supply.

Prosthetic or Orthotic Use: Modifier AV may apply when an eligible item is instead furnished in conjunction with a prosthetic device, prosthetic, or orthotic.

Surgical Dressing Use: Modifier AW may apply when the eligible item is furnished in conjunction with a surgical dressing.

Ineligible HCPCS Code: AU should not be appended indiscriminately to every urological or ostomy supply code.

To Obtain Coverage: Modifier AU cannot make an otherwise noncovered item eligible for Medicare reimbursement.

Billing Example

A Medicare beneficiary uses covered urological supplies and requires an eligible tape product reported with HCPCS code A4450 or A4452.

The tape is furnished specifically for use with the beneficiary's urological supplies.

The supplier reports the applicable HCPCS code with Modifier AU to identify the benefit category under which the item is being furnished.

CMS's current Urological Supplies Policy Article states that A4217, A4450, and A4452 used with urological supplies must be billed with AU.

Documentation Requirements

Underlying Supply: Identify the urological, ostomy, or tracheostomy supply with which the reported item is used.

Clinical Need: Documentation should support the beneficiary's need for the applicable supplies.

Item Furnished: Records should identify the specific item and quantity provided.

Relationship Between Items: Documentation should establish that the AU-designated item was furnished in conjunction with the qualifying supply.

HCPCS Coding: The procedure or supply code should accurately describe the item provided.

Coverage Requirements: Maintain records supporting applicable Medicare coverage and continued-need requirements.

Billing and Claim Considerations

Modifier AU can affect how Medicare categorizes and processes certain DMEPOS items.

For current Medicare urological supply policy, CMS states that A4217, A4450, and A4452 used with urological supplies must carry AU. Claims for these items without AU or another modifier indicating coverage under a different policy may be rejected as missing information.

Tracheostomy policy also requires AU when certain multipurpose supply codes are used with tracheostomy care supplies.

The underlying code matters. Suppliers should not assume that every item associated with urological, ostomy, or tracheostomy care requires AU.

Current Medicare LCDs and related Policy Articles should be checked for the specific item being billed.

Common Billing Mistakes

Omitting AU When Required: Eligible multipurpose supply codes can be rejected when the required benefit-category modifier is missing.

Using AU on Every Supply: The modifier applies to particular items and billing circumstances rather than every urological, ostomy, or tracheostomy code.

Selecting the Wrong Benefit Modifier: AU, AV, and AW distinguish different uses of certain items.

Documentation Does Not Establish Use: Records should demonstrate that the item was furnished in conjunction with the qualifying supply.

Incorrect HCPCS Code: Modifier AU cannot correct an inaccurate underlying supply code.

Assuming AU Establishes Coverage: The beneficiary and item must independently satisfy applicable Medicare coverage requirements.

Common Denial Reasons

Required Modifier Is Missing: Medicare cannot determine the applicable benefit category because AU or another required modifier was omitted.

Incorrect Benefit Category: Documentation indicates the item was furnished for another purpose.

HCPCS Code Does Not Support AU: The modifier is appended to an item for which it is not applicable under the relevant policy.

Medical Need Is Unsupported: Documentation does not establish the beneficiary's need for the underlying supplies.

Quantity Exceeds Coverage Requirements: The number of supplies billed is unsupported or exceeds applicable limits without sufficient documentation.

Claim and Documentation Conflict: The modifier, supply code, quantities, or medical record contain inconsistent information.

Modifier AU vs. AV vs. AW

AU, AV, and AW help Medicare distinguish the benefit category associated with certain multipurpose supplies.

Modifier AU identifies an item furnished with a urological, ostomy, or tracheostomy supply.

Modifier AV identifies an item furnished with a prosthetic device, prosthetic, or orthotic.

Modifier AW identifies an item furnished with a surgical dressing.

Selecting the correct modifier depends on how the item is actually being furnished and the applicable Medicare coverage policy.

Frequently Asked Questions

Does every urological supply require Modifier AU?
No. AU applies to specific items when Medicare policy requires identification of their use with urological, ostomy, or tracheostomy supplies.

What happens if Modifier AU is omitted when Medicare requires it?
For current Medicare urological supply policy, certain applicable codes submitted without AU or another modifier identifying coverage under a different policy can be rejected as missing information.