Nephrology BillingComplete Coding & Revenue Guide (2026)Top CPT codes with current RVU data, denial patterns, modifier rules, bundling pitfalls, and revenue opportunities for nephrology practices.
Top CPT Codes
The highest-value nephrology CPT codes with current RVU data and Medicare payment from the CY 2026 Physician Fee Schedule. Click any code for the full payment, bundling, and modifier guide.
Most practices under-capture revenue on these codes through downcoding, missed modifier 25, stale fee schedules, or misapplied bundling. Our coders audit every line against the documentation before submission so the revenue earned actually gets billed.
Bundling Pitfalls
4 trapsThe code pairs that trigger NCCI edits and CO-97 denials in nephrology. Know these before billing.
90935: 90937: Hemodialysis (90935 single evaluation) vs (90937 repeated evaluation). 90935 = one physician evaluation during HD session. 90937 = re-evaluation needed (complication, hemodynamic instability). Cannot bill both.: 90960: 99214: ESRD monthly capitated codes (90960-90970) are MUTUALLY EXCLUSIVE with outpatient E/M (99213-99215) for the SAME patient in the SAME month. If billing monthly ESRD code, cannot also bill E/M for dialysis-related issues.
90960: 90961: ESRD MCP codes by age and visit frequency: 90960 (4+ visits/month, >20yo), 90961 (2-3 visits), 90962 (1 visit). Age-specific codes exist for <2yo (90963), 2-11 (90964), 12-19 (90965-90966). Bill based on ACTUAL visit count, not planned.
36821: 36831: AV fistula creation (36821) includes the vessel assessment. Separate vessel mapping (93970/93971) on same day is bundled. However, preoperative mapping done on a PRIOR date IS separately billable.
99291: 90935: Critical care (99291) + hemodialysis (90935) same day: separately billable. Critical care time excludes time spent performing/supervising dialysis. Document time separately.
CO-97 bundling denials are recoverable with correct modifier documentation. Most billers write them off. We work each one against the clinical record and resubmit with the right modifier 25 or 59 path.
Modifier Guidance
When to apply each modifier in nephrology claims. Wrong modifier application is the top single-line denial trigger and a leading audit target.
Increased procedural service — use for complex AV fistula revision (multiple prior surgeries, difficult anatomy).
Required on E/M when billing with same-day dialysis access procedure or kidney biopsy. Document the E/M problem separately.
Professional component — use when interpreting renal ultrasound (76770-26), DEXA (77080-26), or dialysis catheter placement fluoroscopy at hospital.
Reduced services — use when providing abbreviated dialysis session (patient leaves early, machine malfunction).
Distinct procedure — use when performing bilateral dialysis access procedures on same date (unusual but possible for tunneled catheter + fistula assessment).
Repeat procedure — same-day repeat dialysis (rare, used for inadequate clearance requiring additional session).
Revenue Opportunities
7 playsThe billing codes and services most nephrology practices under-capture. Each one is a recurring revenue lift, not a one-time fix.
ESRD monthly capitation: 90960 pays $300-450/month per patient. With 30 ESRD patients, that is $108K-162K/year from MCP codes alone. This is the baseline nephrology revenue stream.
In-center dialysis medical directorship: Medical directors earn $1,500-3,000/month per dialysis unit. Typically involves 2-4 hours/month of administrative/quality oversight. Multiple units = significant supplemental income.
Home dialysis training: 90989 (training complete) pays $500-700. Growing demand for home peritoneal dialysis. Each trained patient = recurring revenue from monthly MCP codes (90963-90970 for home patients).
AV fistula creation in-office: 36821 pays $1,500-2,500. Nephrologists with surgical privileges who perform fistula creation capture this revenue vs referring to vascular surgery.
EPO/darbepoetin administration: Buy-and-bill model. Drug cost for darbepoetin ~$300-500/dose, reimbursement $400-700. With 30 ESRD patients getting biweekly dosing = $50K-100K/year drug margin.
CKD education (G0420/G0421): Medicare covers kidney disease education for Stage 4 CKD patients. G0420 (individual, first session) pays $80-120. Up to 6 sessions per patient. Rarely billed but valuable for patient retention and outcomes.
Documentation Checklist
What the chart must contain to support billing. Missing documentation means audit vulnerability.
- CKD management (N18.1-N18.6): Document current GFR and staging, proteinuria quantification (UACR or 24h protein), etiology of CKD, blood pressure with target, medications (ACEi/ARB dose, SGLT2i if applicable), electrolytes (K+, bicarb, phosphorus, calcium), anemia labs (Hgb, iron studies, EPO dose), bone mineral metabolism (PTH, vitamin D), and dietary counseling.
- ESRD dialysis monthly (90960-90970): Document each face-to-face visit during the month — date, clinical status, dialysis adequacy (Kt/V), dry weight assessment, medication review, access assessment. The monthly code covers ALL visits in the month for dialysis-related management.
- AKI management (N17.9): Document baseline creatinine, peak creatinine, probable etiology (prerenal, intrinsic, obstructive), urine output, fluid management, indication for or against dialysis, and renal recovery trajectory.
- Kidney biopsy: Document indication (proteinuria quantification, hematuria workup, AKI etiology, transplant rejection), pre-procedure coagulation status, technique (percutaneous vs open), number of cores obtained, complications, and pathology results.
- Dialysis access (36818-36833): Document access type (AVF vs AVG), vessel assessment, anastomosis technique, patency confirmation, complications, and post-procedure plan. Include maturation timeline for new fistulas.
Coding Workflow
Step by step approach for coding nephrology encounters correctly.
1. Determine encounter type: outpatient CKD management (E/M codes) vs ESRD monthly management (90960-90970) vs inpatient (99221-99223) vs critical care (99291). 2. For CKD patients: stage by GFR, code to highest specificity (N18.30 vs N18.31 vs N18.32), document etiology (diabetic = E11.22, hypertensive = I12.9). 3. For ESRD patients: count face-to-face visits per month to select correct MCP code (90960 for 4+, 90961 for 2-3, 90962 for 1). 4. For dialysis: 90935 per session with single evaluation, 90937 if re-evaluation needed. 5. Bill EPO/darbepoetin (J0882/J0881) separately with appropriate units. 6. For access procedures: bill creation (36818-36821), revision (36831-36833), or declot (36831) with appropriate modifiers. 7. Check for anemia (D63.1), secondary hyperparathyroidism (E21.1), electrolyte disorders — each is separately codeable.
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Everything about Nephrology billing
What CPT codes does Nephrology bill most often?
Top Nephrology codes include 99214 (Established patient office visit, moderate MDM or 30-39 minutes); 99215 (Established patient office visit, high MDM or 40-54 minutes); 99213 (Established patient office visit, low MDM or 20-29 minutes); 99223 (1st hosp ip/obs high 75); 99232 (Sbsq hosp ip/obs moderate 35).
What are the most common denials in Nephrology billing?
Nephrology denials concentrate around medical necessity, bundling, prior authorization, and modifier errors.
Does Go Medical Billing handle Nephrology?
Yes. Go Medical Billing handles Nephrology billing with AAPC-certified coders, payer-specific scrub rules, and dedicated account management. Starting at 2.49 percent of collections with no setup fees.
Specialty content reviewed by AAPC-certified coders. CPT codes and descriptions are copyright of the AMA. Medicare payment varies by locality. Commercial rates vary by contract.
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