Question: Our new patient was referred for aftercare following amputation of his left foot due to diabetic gangrene caused by diabetic angiopathy. How should we code for him in ICD-9? How will our coding change in ICD-10 Oregon subscriber?
Answer: Code for this patient as follows in ICD-9:
Your focus of care for this patient is aftercare following his amputation surgery. Your principal diagnosis for this patient is V54.89.
He had surgery to address the gangrene caused by his diabetic peripheral angiopathy (443.81) in his left foot. Your patient’s surgery removed the gangrene, but didn’t resolve the patient’s diabetes or his peripheral angiopathy, so you should list these codes in M1022b and M1022c. In Appendix D of the OASIS-C Guidance Manual, the Centers for Medicare & Medicaid Services instructs you to sequence the underlying condition next after listing the V code in the principal diagnosis slot, so you should not move those diagnoses further down in M1022.
Finally, list V49.73 to indicate your patient’s foot amputation status.
In ICD-10, you would report the following codes for this patient:
Once again, you’ll list an aftercare code as the principal diagnosis. In ICD-10, your principal diagnosis is Z47.81.
Next you’ll want to report the reason for the patient’s surgery. In ICD-10, one combination code describes the patient’s diabetes and the manifestation of peripheral angiopathy. The patient’s gangrene was removed, so it wouldn’t be appropriate to report E11.52 (Type 2 diabetes mellitus with diabetic peripheral angiopathy with gangrene).
Finally, list Z89.432 to indicate that the patient’s left foot was amputated.
Note: When coding for a traumatic amputation, you won’t use the aftercare code for traumatic injuries in ICD-10. The code for the traumatic amputation of the left foot at the ankle is S98.012D (Complete traumatic amputation of left foot at ankle; subsequent encounter). You also won’t list the Z89 status code for acquired absence because the traumatic amputation code provides the information. You aren’t required to include the external cause code for how the traumatic amputation occurred, but reporting it is encouraged.