A patient presents due to abdominal pain. At discharge, the provider documents “Acute pyelonephritis and nephrolithiasis.” When referencing pyelonephritis in the Alphabetic Index there are subentries for “acute” and “with calculus” at the same indentation level. Should only the combination code describing calculus with pyelonephritis be assigned, or are separate codes assigned? What is the appropriate code assignment for acute pyelonephritis with calculus?
Assign codes N10, Acute pyelonephritis, and N20.0, Calculus of kidney, for acute pyelonephritis with nephrolithiasis. In this case, the code assignment differs from the previous question above, because the provider specifically documented “acute pyelonephritis.” When referencing “Pyelonephritis, acute” in the Index, the coding professional is directed to code N10, Acute pyelonephritis, rather than code N20. In addition, there are no Excludes1 notes prohibiting the assignment of codes for acute pyelonephritis and renal calculus together.