Q&A: Coding highest level of specificity for kidney disease

Q: A patient presented to the hospital for a coronary artery bypass graph (CABG) and stage 4 chronic kidney disease (CKD). After surgery, the physician documented additional kidney damage, end stage renal disease (ESRD), and dialysis. ESRD is a MCC, however, the coder thinks we cannot code the ESRD because the patient would need to be on chronic dialysis, prior to the admission.

A: Documentation and coding requirements related to renal disorders and diseases can be confusing, even for those of us with numerous years of experience.

Per the Official Guidelines for Coding and Reporting ICD-10-CM, the coding of CKD is based on the severity of the disease, designated by stages 1-5, based on the GFR (glomerular filtration rate) as follows:

• Stage 2, code N18.2 equates to mild CKD
• Stage 3, code N18.3, equates to moderate CKD
• Stage 4, code N18.4, equates to severe CKD
• ESRD, code N18.6

ESRD should be assigned when the provider documents it. If the provider documents both a stage of CKD and ESRD, only the code for ESRD (N18.6) is assigned. Some of the confusion regarding the code assignment may be due to the fact that if you look up ESRD (N18.6) in a code book, under the main bolded term of End Stage Renal Disease there is an inclusion term for CKD “requiring chronic dialysis.” This, however, is not part of the code description. The code description merely states ESRD. Based on the instructional notes, we would also “use additional code” to identify dialysis status (Z99.2) The difference between Stage 5 CKD and ESRD is that ESRD requires chronic dialysis.

Editor’s Note: Sharme Brodie, RN, CCDS, CDI education specialist and CDI Boot Camp instructor for HCPro in Middleton, Massachusetts, answered this question. For information, contact her at sbrodie@hcpro.com. For information regarding CDI Boot Camps offered by HCPro, visit www.hcprobootcamps.com/courses/10040/overview.