Nephrology practices manage chronic kidney disease, end-stage renal disease, dialysis, electrolyte disorders, and kidney transplant follow-up. Accurate ICD-10 coding and ESRD billing are critical for Medicare reimbursement under the ESRD Prospective Payment System. This page covers the top codes used by nephrologists in the US.
FY 2026 ICD-10-CM (CMS) · CPT codes updated annually · All codes verified billable · Last verified: June 2026
Creation of arteriovenous fistula, non-autogenous graft
N/A
-RT, -LT, -59
50200
Renal biopsy, percutaneous, by trocar or needle
N/A
-26, -TC, -RT, -LT
*Approximate 2025 CMS national non-facility rate. Rates vary by geography, setting, and payer contract. Refer to the CMS Physician Fee Schedule for official rates.
Top Denial Reasons for Nephrology Claims
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Medical Necessity Not Documented
Claims for dialysis management or CKD monitoring are denied when physician notes lack explicit documentation of the stage of kidney disease and current GFR/lab values. Ensure every encounter note references the specific CKD stage, relevant labs, and clinical rationale for the visit frequency.
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Missing or Incorrect Modifier on ESRD Monthly Services
ESRD monthly capitation codes (90960-90962) are denied when the -GV (physician supervising but not owner of ESRD facility) or -GW (unrelated to ESRD) modifier is omitted or applied incorrectly. Verify modifier selection based on the physician’s relationship to the dialysis facility before submission.
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Diagnosis-Procedure Code Mismatch
Hemodialysis or peritoneal dialysis CPT codes submitted without a supporting ESRD/CKD diagnosis (N18.6, Z99.2) trigger automatic edits and denials. Always link dialysis procedure codes to the correct ICD-10 diagnosis and ensure the claim’s diagnosis pointer is correctly assigned.
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Prior Authorization Not Obtained for AV Fistula Creation
Surgical access creation codes such as 36818-36830 frequently require prior authorization from commercial and Medicare Advantage plans, and claims without a valid auth number are denied on first pass. Confirm authorization requirements and obtain approval before scheduling the procedure.
Nephrology Billing & Coding Tips
Always code the CKD stage (N18.1–N18.6) — non-specific N18.9 (CKD, unspecified) does not capture the correct HCC weight and may trigger MRA queries.
Z99.2 (dependence on renal dialysis) should be added to all encounters for ESRD patients on hemodialysis or peritoneal dialysis.
Combine I12.x or I13.x with the appropriate N18.x code when hypertension coexists with CKD — do not code I10 separately.
90935 (hemodialysis, single evaluation) is for in-office dialysis; hospital dialysis uses different E&M dialysis codes (99261–99263, 99291).
N18.3 is Chronic kidney disease, stage 3. CMS further delineates N18.31 (Stage 3a, GFR 45–59) and N18.32 (Stage 3b, GFR 30–44) for specificity. Always code to the most specific stage supported by the GFR value documented in the chart.
What is the correct code for ESRD?
N18.6 is End-Stage Renal Disease. It is required for all ESRD patients on dialysis. Add Z99.2 (dependence on renal dialysis) as an additional code when applicable. ESRD patients are covered under Medicare Part B regardless of age.
When should I use I12 vs I10?
When hypertension and CKD coexist, code I12.9 (hypertensive CKD, stage 1–4) or I12.10 (with stage 5 CKD or ESRD). Do not code I10 and N18.x separately — ICD-10 convention assumes a causal relationship between hypertension and CKD.
What CPT code is used for dialysis?
90935 covers hemodialysis with one physician evaluation. 90937 is used when multiple physician evaluations occur during a hemodialysis session. Peritoneal dialysis uses 90945 (single evaluation) or 90947 (multiple evaluations).
How does OmniMD support nephrology practices?
OmniMD’s Nephrology EHR includes CKD staging calculators, eGFR tracking, ESRD monthly capitation billing tools, and integrated lab result feeds from major dialysis centers.
Streamline Your Nephrology Practice with OmniMD
Purpose-built EHR, billing, and practice management for Nephrology practices.
