Modifier A7

Dressing for seven wounds

Modifiers A1-A9 have been established to indicate that a particular item is being used as a primary or secondary dressing as well as to indicate the number of wounds on which that dressing is being used. If a dressing is not being used as a primary or secondary dressing on a surgical or debrided wound, the use of the A1-A9 modifiers would be inappropriate.

Dressings for surgical or debrided wounds must include one of the A1-A9 informational modifiers. The correct modifier to use is the number that corresponds to the number of wounds the dressing will be used for, NOT the number of wounds the beneficiary has.

Also be aware that it would be inappropriate to use these modifiers to identify the number of times the beneficiary is to be changing their dressings per day. The frequency of changes must be clearly indicated on the order based on the ordering physician's direction.


  • Gradient compression stockings/wraps (HCPCS A6531, A6532 and A6545)
    • These HCPCS should not be billed with A1-A9 modifiers when they are used for an open venous stasis ulcer
  • Multiple wounds that require the same type of dressing and multiple dressings are needed for those wounds
    • Example, a beneficiary has seven wounds, each requiring same type of dressing but the wounds are located too far apart for one single dressing to be used. Typically, if one dressing is used for one wound the A1 modifier would be used. In this situation, you cannot bill seven line items with the same HCPCS because they will deny as a duplicate in the claim processing system. Therefore, one line item will be billed with the A7 modifier because the same type of dressing is being used on seven wounds and seven units of service.

Appeal Option

Because the actual HCPCS codes require additional documentation and review, and are considered too complex, suppliers cannot submit a Reopening request for adding, changing or removing of the A1-A9 modifiers.

Such requests must be submitted via a Redetermination request.



Last Updated Sep 27 , 2022