Can I Assume CKD Stage Based Solely on eGFR Level?
Question: Thank you so much for your guidance on coding the different stages of chronic kidney disease (CKD) in your answer to the reader question “Get to Know the Different CKD Stages.” I have a follow-up question: If a provider documents that a patient has stage 3 CKD, but does not specify whether it is 3a or 3b, can I document the stage based on the patient’s documented estimated glomerular filtration rate (eGFR) level? Revenue Cycle Insider Subscriber Answer: No, you cannot interpret a patient’s eGFR level and assign a code yourself. When the CKD codes with their corresponding stages were first introduced in 2020, they were the subject of an AHA® ICD-10-CM/PCS Coding Clinic article, “Stage 3 Chronic Kidney Disease” (Volume 7, Number 4, 2020), which stated that “Code assignment should be based on provider documentation of the stage.” This means you cannot assign N18.31 (Chronic kidney disease, stage 3a) or N18.32 (Chronic kidney disease, stage 3b) even if the documentation specifies the patient’s eGFR is 45 to 59 (for N18.31) or 30 to 44 (for N18.32). Instead, you will need to query your provider for the correct stage before assigning a code. And if the documentation does not specify the patient’s eGFR, you will have to assign N18.30 (Chronic kidney disease, stage 3 unspecified). Having the correct CKD stage is essential for several reasons, one of which being the hierarchical condition category (HCC) risk adjustment model. Each CKD stage carries a different HCC value, which affects risk adjustment factor (RAF) scores and how payers and healthcare practices distribute resources and manage patient risk. For more information about HCC, refer to the AAPC Knowledge Base article “Get Ready for CMS-HCC V28.” Bruce Pegg, BA, MA, CPC, CFPC, Managing Editor, AAPC
