Nephrology Medical Billing: ESRD, CKD & Coding

Nephrology billing is built around bundled payment models that work differently from most medical specialties. 

The ESRD Monthly Capitation Payment (MCP) — the largest revenue source for most nephrology practices — pays a single monthly amount for physician supervision of dialysis patients, not a per-visit fee. 

Selecting the correct MCP code depends on patient age and the number of face-to-face visits that month. Get the visit count wrong, and the claim either pays less than earned or gets denied entirely. 

Beyond the MCP, nephrology practices: 

• CCM/TCM
• Dialysis session procedures
• Vascular access interventions
• Bill E/M services for CKD management

Each following different CMS rules and different bundling logic. In this read, let’s cover:

• CKD staging and its direct impact on claim acceptance
• Dialysis session billing (and when it’s appropriate alongside MCP)
• The five denial patterns that cost nephrology practices the most revenue
• ESRD Monthly Capitation Payment codes and how visit count determines reimbursement

How is nephrology billing structured?

Nephrology billing operates across three revenue domains, each with distinct CMS payment logic.

Revenue Category	Description
Dialysis supervision and ESRD management	Billed monthly through MCP codes (90951-90970) and typically represents the largest revenue source for nephrology practices.
Outpatient clinic visits	Billed through standard E/M codes (99202-99215) for chronic kidney disease management, hypertension, electrolyte disorders, and pre-dialysis care.
Procedures	Includes vascular access creation, access revision, thrombectomy, catheter placement, and kidney biopsies billed under applicable surgical CPT codes.

The billing challenge specific to nephrology is that these domains overlap in the same patient. 

An ESRD patient on in-center hemodialysis may receive MCP-covered supervision, a separately billable E/M for a non-dialysis problem, and a vascular access procedure — all within the same month. 

Each service follows different rules, and getting the interaction wrong is where most denials originate.

How do ESRD monthly capitation payment codes work?

The MCP is how Medicare pays nephrologists for ongoing ESRD patient management. 

Instead of billing per visit, the nephrologist reports a single monthly code covering all physician supervision, assessments, and care coordination for that patient.

MCP code selection depends on two factors — patient age and monthly face-to-face physician visit count.

The revenue gap between 90960 and 90962 is often $100+ per patient per month. 

For a practice managing 200 ESRD patients, the gap between consistently billing 90960 versus defaulting to 90962 because visit documentation is incomplete represents hundreds of thousands of dollars annually. 

The billing code is simple. The hard part is making sure visit counts are documented and accurate every month for every patient.

When are dialysis session codes appropriate?

Dialysis session codes are separate from MCP. MCP covers monthly physician supervision. Session codes cover the actual dialysis procedure when a physician provides direct evaluation during the session.

CPT code	Description
90935	Hemodialysis with single physician evaluation
90937	Hemodialysis with repeated physician evaluation
90945	Non-hemodialysis (e.g., peritoneal), single evaluation
90947	Non-hemodialysis, repeated evaluation

A common mistake is billing both MCP and a session code for the same routine supervision. 

Session codes apply only when the physician provides a distinct evaluation beyond what the MCP covers (evaluating an acute complication during dialysis, for example). 

Billing both for routine supervision is a bundling violation that CMS auditors specifically target.

How does CKD staging affect nephrology billing?

CKD staging directly affects claim acceptance. Payers require specific ICD-10-CM codes identifying the stage, and using an unspecified code when staging data is available triggers automatic denials.

ICD-10-CM	CKD stage	GFR range (ml/min/1.73m²)
N18.1	Stage 1 (damage, normal GFR)	≥90
N18.2	Stage 2 (mild decrease)	60-89
N18.31 / N18.32	Stage 3a / 3b	45-59 / 30-44
N18.4	Stage 4 (severe decrease)	15-29
N18.5	Stage 5 (not yet on dialysis)	<15
N18.6	End-stage renal disease	On dialysis or transplant

The billing impact goes beyond claim acceptance. Stage determines which services are covered, which monitoring codes apply, and when a patient transitions from CKD management (E/M billing) to ESRD management (MCP billing). 

A patient coded N18.5 who begins dialysis should transition to N18.6 and MCP billing — but if the diagnosis isn’t updated, the practice continues billing E/M visits while missing MCP revenue, or creates conflicting claims.

For most nephrology practices, maintaining accurate CKD staging in the EHR — updated at every visit based on current GFR — is a billing prerequisite, not just a clinical documentation task.

When can E/M visits be billed alongside MCP?

E/M visits for ESRD patients already covered by MCP must represent a separately identifiable service. Modifier 25 is appended to indicate a significant, distinct clinical encounter.

E/M billing is appropriate when the patient presents with a non-dialysis problem (acute infection, new cardiac symptom, medication reaction unrelated to ESRD), the service addresses a condition distinct from MCP coverage, and documentation supports a separate diagnosis and management plan.

E/M billing is not appropriate when the visit addresses routine dialysis management already covered by the monthly capitation, or when the physician simply checks on the patient during a scheduled session without addressing a distinct problem.

Modifier 25 misuse is one of the highest-risk audit triggers in nephrology. 

Appending modifier 25 without documentation of a distinct non-dialysis clinical problem converts a legitimate MCP visit into a compliance violation — and CMS auditors look specifically for E/M codes with modifier 25 billed alongside MCP on the same date of service.

What documentation do nephrology claims require?

CMS and MACs require documentation that supports every element of the claim, and the standards differ by service type.

MCP documentation

MCP documentation must include the number of face-to-face visits that month (must match the reported CPT code), dialysis modality, adequacy metrics (Kt/V where applicable), vascular access type and status, care plan updates, and complications addressed. 

A single missing visit note — one physician encounter that was performed but not documented — can drop a patient from 90960 to 90961 for that month. 

Across hundreds of patients, documentation gaps represent the largest single source of nephrology revenue leakage.

E/M documentation

E/M documentation must include CKD staging with current GFR, comorbidity management, medication reconciliation, dialysis status, and clinical reasoning supporting the level billed. 

Vascular access documentation must clearly distinguish between diagnostic imaging and therapeutic intervention, with separate documentation for each procedural component.

What about CCM and TCM in nephrology?

CKD patients not yet on dialysis often qualify for CCM and TCM, creating additional revenue beyond standard E/M.

CCM is billable when a patient has 2+ chronic conditions expected to last 12+ months with a structured care plan — CKD patients with diabetes, hypertension, or cardiovascular disease almost always meet the threshold

TCM is billable after hospital discharge when the nephrologist provides follow-up within specified timeframes — particularly relevant for CKD patients at high readmission risk

Many practices underbill both because time-tracking and care coordination documentation create workflow overhead that billing teams don’t capture consistently. The clinical work is happening — the revenue gap is a documentation capture problem, not a service delivery problem.

Nephrology billing requires precision across every revenue stream

MedHeave helps nephrology practices optimize ESRD monthly capitation payments, CKD billing, dialysis-related services, and chronic care management by aligning documentation, coding, and claim submission with nephrology-specific reimbursement rules. 

Our team focuses on the areas where nephrology practices lose the most revenue — inaccurate MCP visit counts, CKD staging errors, modifier 25 compliance issues, and missed CCM opportunities.

• CKD staging and diagnosis coding accuracy reviews
• Dialysis, E/M, and modifier 25 compliance monitoring
• Dedicated account managers with full reporting visibility
• CCM and TCM documentation capture and billing support
• ESRD MCP coding and visit-count validation (90960–90962)

If documentation gaps, MCP coding errors, or dialysis billing denials are creating preventable revenue loss in your practice, contact us to learn how MedHeave helps nephrology groups improve reimbursement accuracy and capture the revenue they’ve already earned.

Frequently asked questions

Here are some commonly asked questions about nephrology medical billing: