27134 vs. 27137

Question:

What is the correct way to bill for a hip arthroplasty revision where the full acetabular component is replaced, and a new femoral head is placed, but nothing is done to the femoral stem?

Answer:

Thank you for asking KZA!

Admittedly, this is a frustration.

The CPT descriptor for 27137 is for revision of hip arthroplasty, acetabular component only. Based on the scenario described, it would not be appropriate to report 27137, as both the acetabular component and femoral head were revised.

The CPT descriptor for 27134 is for revision of hip arthroplasty, both components. A hip arthroplasty comprises the acetabular and femoral components (femoral head and femoral stem).

From a correct coding standpoint, both hip arthroplasty components have not been completely revised – we only have the acetabular and part of the femoral component (femoral head). Therefore, it would be appropriate to append modifier 52 to reflect the reduced services.

At the time of this writing, this is the current guidance from CPT.

*This response is based on the best information available as of 7/31/25.