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Wound vs. Ulcer: Selecting the Correct Diagnosis Code

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It has come to this author’s attention that there are many coding questions regarding wound versus ulcer diagnosis coding. Hopefully, this article will eliminate the confusion between wounds and ulcers. 

From the coding perspective, there are 2 major categories of wounds: acute (wound) and chronic (ulcer). Acute wounds are classified by many coding terms, e.g.:

  • Superficial injuries include the terms contusions, abrasions, blisters, external constriction, superficial injuries with foreign bodies, insect bites (non-venomous and venomous), and other superficial bites.  
  • Open wounds include lacerations with and without foreign bodies, puncture wounds with and without foreign bodies, trauma wounds, and open bites.  
  • Skin trauma codes include crush injuries, partial and total traumatic amputations, burns and corrosions, open fractures, and frostbite.
  • Surgical wounds. 
  • Wounds caused by other acute diseases such as acute and subacute osteomyelitis.  
  • Surgical complications of grafts and surgical wounds.

See Table 1 for an example (using the foot as the site of the injury) of how the superficial injury codes and open wound codes appear in the ICD-10-CM index. Reminder: Any code that appears in Chapter 17 of ICD-10-CM: Injury, poisoning and certain other consequences of external causes, requires a 7th character of (A) initial encounter (which means active treatment being rendered to the wound), (D) subsequent encounter for the same wound, or (S) sequela of the wound. 

Chronic wounds are classified by different coding terms that are familiar to most readers, e.g.:

  • Pressure ulcers
  • Non-pressure ulcers
  • Varicose veins with ulcers
  • Atherosclerotic disease with ulcers
  • Diabetic ulcers
  • Chronic osteomyelitis

See Table 2 for examples of many of the chronic ulcer categories. Chronic ulcers usually have an underlying cause associated with the ulcer (diabetes, venous disease, etc.) Please note that these codes are not in Chapter 17 and do not require the addition of the 7th character as described for the acute wounds discussed above. 

Do You Need a Wound Code or an Ulcer Code?

Following are some tips to help you decide whether to select a wound code or an ulcer code. 

  1. The basic rule of thumb is to code each ulcer or wound separately. If multiple sites are treated at the same encounter, select the diagnosis code that identifies each wound or ulcer. If the wounds or ulcers are similar but their diagnosis codes are even different by one single character, each site’s diagnosis code should be reported. 
  2. From a coding guideline perspective, there is no timeline during which an acute wound turns into a chronic ulcer. Remember, a nonhealing surgical wound code is listed as a complication in the injury chapter of ICD-10-CM.  
  3. The progress of all acute injury and wound codes in Chapter 17 can be delineated by using the 7th character (A, D, S). 
  4. Always match the treatment rendered to the appropriate wound or ulcer site code. Multiple wounds or ulcers may often receive different treatments on the same date of service. Linking the right diagnosis code to the treatment makes it easy for the payer to understand 1) the longitudinal treatment of a single wound or ulcer, and 2) which treatments were provided to multiple wounds or ulcers.
  5. If infection is present, use additional codes to describe an infection agent. If the infection is due to surgery, use post-op complication codes. If the infection is not due to surgery, add the additional organism code(s). 
  6. From a coding perspective, the underlying cause of a chronic ulcer is listed first and the type of ulcer (e.g., pressure ulcer or non-pressure ulcer) is listed second. Caution: Payers’ coverage guidelines often require the chronic ulcer to be listed first.   
  7. If a complication is related to a previous open or traumatic wound that has since closed, use the site of the wound with sequela (S) to indicate a relationship to a previous wound or injury.
  8. The first listed code for an outpatient clinic/office visit may not always be the wound or ulcer itself. It could be a complication, an infection, and/or a new wound or ulcer of a different site. Ask yourself, “What diagnosis required most of the treatment during the clinic/office visit?”

In Conclusion

I hope that this article has clarified some of the confusion on wounds versus ulcers and provided you with some specific examples to think about. While this article is not all-inclusive, it should be indicative of how, from a coding perspective, acute wounds and chronic ulcers are delineated. Physicians and other qualified healthcare professionals should know whether to diagnose the problem as a wound or an ulcer. 

Donna Cartwright is senior director of health policy and reimbursement at Integra LifeSciences Corp., Plainsboro, NJ. She is approved as a certified trainer on ICD-10-CM by the American Health Information Management Association and she has been designated as a fellow of the American Health Information Management Association. 

Donna Cartwright, MPA, RHIA, CCS RAC, FAHIMA
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