One of the most important steps to ensure clean billing of surgical dressings is the appropriate use of the A- modifier. The A- modifier must be used to indicate two things:

  1. Is the dressing billed for a primary or secondary dressing?
  2. How many wounds are being treated with the dispensed dressing? An important differentiation is that this is not the number of wounds present, but rather the number of wounds being treated.

Form 1500 A- Modifier

Example of Form 1500 for AMERX 30-Day Collagen Wound Care Kit being used to treat a single wound.

Click the image to
view at a larger size.

A- Modifer Should Be In Box 24d

The A- modifer should be listed in box 24d of the CMS-1500 form (Health Insurance Claim Form). For those that employ electronic billing and do not manually complete the 1500 form, be sure to include the A- modifier in the modifier section of your software and the software should be programmed to allow for proper modifier placement and submission. This must be present every time surgical dressings are billed for. The number that immediately follows the “A” in the modifier is the number of wounds being treated. For example, if two wounds are being treated with the dressings being dispensed, the modifier would be “A2”. This must be done even when only one wound is being treated, indicated with modifier “A1”.

Common Errors

One common error is not including the A- modifier at all. Another is the incorrect thought that the A- modifier is only needed the first time surgical dressings are dispensed to a patient or only when a change in dressings is made. Some make the mistake of using the A- modifier to indicate how many times a week the dressing will be changed.

A- Modifier Not For Compression Garments

The exception to the need for the A- modifier with surgical dressings is found with compression garments. The A- modifier should not be used with compression wraps/garments. When coding for the EXTREMIT-EASE Compression Garment, use the product code of A65545, but do not use an A- modifier in box 24d of the CMS-1500 form.

Stay Tuned!

The A- modifier is only one of the important modifiers to be aware of when coding for surgical dressings. Look for next month’s blog post which will focus on the -AW and laterality modifiers.


Dr. Jeffrey D. Lehrman, DPM, FASPS, MAPWCA, CPC
Dr. Jeffrey D. Lehrman, DPM, FASPS, MAPWCA, CPC, CPMA

Dr. Lehrman is a podiatrist practicing in Fort Collins, CO and operates Lehrman Consulting, LLC which provides consultation services regarding coding, compliance and documentation. Dr. Lehrman is a Certified Professional Coder and Certified Professional Medical Auditor. He serves as a staff liaison at the AMA CPT® Editorial Panel meetings where CPT codes are created, edited, and deleted. He is a Diplomate of the American Board of Foot and Ankle Surgery, Fellow of the American Society of Podiatric Surgeons, and is recognized as a “Master” by the American Professional Wound Care Association. Dr Lehrman is a Fellow of the American Academy of Podiatric Practice Management, Past Director of the American Professional Wound Care Association Board of Directors, and is a Past Chairman of the Board of the American Society of Podiatric Surgeons. Dr. Lehrman is also on the editorial advisory board of the journal WOUNDS.