Question: Out home health agency is providing skilled nursing and physical therapy for a new patient following a below knee amputation due to gangrene. He is receiving gait training as well as aftercare for the surgery. How should we code for him?
Answer: Report the following codes for this patient:
· M1020a: V58.49 (Other specified aftercare following surgery);
· M1022b: 781.2 (Abnormality of gait); and;
· M1022c: V49.75 (Lower limb amputation status; below knee).
Your focus of care for this patient is aftercare for his amputation surgery, so V58.49 is the appropriate principal diagnosis code when the reason for the surgery was gangrene.
Tip: Alternate aftercare codes for this situation are V54.89 (Other orthopedic aftercare) which includes aftercare following amputation and V58.73 (Aftercare following surgery of the circulatory system, NEC) because this type of gangrene is associated with ischemia.
Your patient’s gangrene was resolved by the surgery, so it’s not appropriate to list it in M1022, and you can no longer code for resolved conditions in M1024. So reporting 785.4 (Gangrene) isn’t appropriate for this patient.
There is no loss of case mix points in this scenario because gangrene only receives points when you report it with a manifestation code and accompany this with an acceptable etiology. If the gangrene had been associated with diabetes, however, there could potentially be a loss of 5-12 case mix points as well as loss of 8 or 11 NRS points.
To avoid coding a condition no longer present, you can instead code the symptom that is now the focus of care, in this case abnormality of gait, which you can list in M1022b.
Follow this with V49.75 to indicate that your patient had a below knee amputation.