Revenue Cycle Insider

Question: I have a coding question on bilateral upper extremity vein mapping. My facility is struggling with the diagnosis to support medical necessity for upper vein mapping for initial arterial inflow and venous outflow (AV) hemodialysis access. We are billing 93985 for this procedure. The patient currently has end stage renal disease (ESRD) and is about to start hemodialysis, so it is important to note that this is a preoperative evaluation.

What diagnosis codes would be appropriate for this service?

Kentucky Subscriber

Answer: Let’s start with the reason for the study — your patient has ESRD. In the ICD-10-CM Alphabetic Index, search for the main term “Disease.” Once you locate “Disease,” find the term “renal.” Under the term “renal,” you should see the subterm “end-stage (failure) N18.6.” Next, you’ll go to your Tabular List to confirm N18.6 (End stage renal disease) is the correct diagnosis for the ESRD.

Also, since this is a preoperative evaluation, we need to add an applicable ICD-10-CM code to the claim. In the Alphabetic Index, search for the main term “Examination.” Once you locate “Examination,” find the term “pre-procedural (pre-operative).” Under the term “pre-procedural (pre-operative),” you will see “specified NEC Z01.818.” Under “pre-procedural (pre-operative),” you will see specificity for cardiovascular, laboratory, and respiratory — but since this is renal, we will use specified NEC. Verify Z01.818 (Encounter for other specified special examinations) is the correct code in the Tabular List. Next, you’ll focus on sequencing the diagnosis codes.

The order of the diagnosis codes on a claim can have a large impact on whether the patient’s payer covers a service. When you look at Z01.818 in the Tabular List, you will notice that there is a Z-1 icon attached to the diagnosis code. The Z-1 icon means that this diagnosis code must be used in the primary diagnosis position on the claim. Therefore, the correct diagnosis code order for this service should be Z01.818 as primary and N18.6 as secondary.

To further confirm the diagnosis order, we can also look to Local Coverage Articles (LCAs) for diagnosis order information. If you examine >LCA 56697, you will see information on 93985 (Duplex scan of arterial inflow and venous outflow for preoperative vessel assessment prior to creation of hemodialysis access; complete bilateral study) under group 6. When you scroll down toward the bottom of the LCA, you will find the diagnosis order instructions for group 6. The group 6 paragraph instructions state, “List the Z01.818 (Encounter for other preprocedural examination) as the primary diagnosis. The secondary diagnosis ‘should identify the reason for the study and/or findings.’”

Kaitlyn Brack, CPC, CPMS, CEMC, CFPC, CPEDC, Approved Instructor, Medical Coding Auditor and Educator,
Baptist Health Deaconess, Madisonville, Kentucky