Specialty Billing Built for Nephrology Practices

Dialysis code selection is driven by modality and reassessment status. Hemodialysis is billed with 90935 (single physician evaluation) or 90937 (with reassessment) when a repeated evaluation occurs in the same month. Peritoneal dialysis uses 90945 (single evaluation) or 90947 (with reassessment). The reassessment codes pay for a second, separate physician evaluation and are frequently missed. We select the base code by modality (HD vs PD) and bill the reassessment code only when a documented second evaluation occurs, so neither the base dialysis payment nor the reassessment revenue is lost.

AV fistula creation is billed with 36818 (direct AV anastomosis, any site) or 36821 (direct AV fistula), and AV graft creation uses 36830 with revision via 36833. These are separately reportable procedures when performed in a distinct session from dialysis management, but payers sometimes deny them as bundled. Modifier 59 (distinct procedural service) is appended when the access procedure is performed on a separate date or is clearly distinct from related services. We document the access creation session and append modifier 59 where appropriate so vascular access procedures are paid rather than denied as bundled into dialysis E/M.

Renal ultrasound, dialysis-access vascular imaging, and related radiology codes have a professional component (interpretation, modifier 26) and a technical component (equipment and testing, modifier TC). When a nephrologist interprets an image performed by a facility or outside provider, only the 26 is billed. When the practice owns the equipment, the TC or global is billed per payer rules. Medicare requires the components split when a facility is involved. We apply the correct 26/TC split per payer on every renal and dialysis imaging claim so neither the professional interpretation nor the technical component is lost to a global-only denial.

CKD is staged by GFR into N18.1 (stage 1), N18.2 (stage 2), N18.3 (stage 3), N18.4 (stage 4), and N18.5 (stage 5 / CKD on dialysis), with N18.6 (end-stage) and N18.9 (unspecified). Accurate staging drives severity-adjusted reimbursement and ESRD E/M eligibility. Dialysis dependence is captured with Z99.2 (dependence on renal dialysis), and transplant status with Z94.0. We pair every nephrology encounter with the correct N18.x stage, add Z99.2 when the patient is on dialysis, and Z94.0 post-transplant, so severity adjustment and ESRD monthly E/M eligibility are never lost to a generic N18.9 unspecified code.

Chronic care management (MCP) base code 99490 covers the first 30 minutes of clinical staff time directed by a physician per calendar month for patients with two or more chronic conditions, and requires an established care plan, patient consent, and 24/7 access. The 99439 add-on bills each additional 20 minutes of chronic care time in the same month. Denials happen when the care plan, consent, or the 20-minute time threshold isn’t documented. We verify the care-plan record, consent on file, and documented time before billing 99490, and bill 99439 only when additional documented time crosses the 20-minute add-on threshold, so MCP chronic-care revenue is captured cleanly.