Nephrology billing is one of the most complex specialties in healthcare. Between monthly capitation payments for end-stage renal disease (ESRD), bundled dialysis services, and strict Medicare documentation rules, even experienced billing teams make costly mistakes. The result? Denied claims, lost revenue, and audit exposure that puts your practice at risk.
Contact AMS Solutions today for a free consultation and find out how our nephrology billing specialists can help your practice collect every dollar it earns.
This guide breaks down how nephrology and dialysis billing works, the most common errors practices make, and what to look for in a billing partner who actually understands renal care.
Why Nephrology Billing Is Different from Other Specialties
Most medical specialties bill on a per-visit or per-procedure basis. Nephrology does not follow that model for a large portion of its patient population. ESRD patients, those requiring regular dialysis, are billed under a monthly capitation payment (MCP) structure through Medicare. This means the nephrologist receives one monthly payment that covers all routine care for that patient during the month.
That monthly payment amount depends on how many face-to-face visits the physician documents during the calendar month and whether the patient receives dialysis in an outpatient center or at home. Selecting the wrong CPT code because visit counts were not tracked accurately is the single most common nephrology billing error, according to revenue cycle specialists across the industry.
On top of the MCP structure, nephrology practices also manage:
- CKD patients (stages 1-4) who bill under standard evaluation and management (E/M) codes with precise ICD-10 staging requirements
- Dialysis procedure billing for hemodialysis and peritoneal dialysis sessions that fall outside the monthly bundle
- Medicare compliance obligations that are more intensive than nearly any other specialty, including data monitoring, audit exposure, and bundling rules
- Multiple payer coordination involving Medicare as primary, commercial insurance, and Medicaid secondary coverage for dual-eligible patients
A billing team without nephrology-specific experience will struggle to keep these billing models straight, and the financial consequences add up fast.
Key CPT Codes Every Nephrology Practice Should Know
Accurate coding is the foundation of nephrology revenue. Here are the CPT codes that drive the majority of nephrology billing.
ESRD Monthly Capitation Payment (MCP) Codes
These codes cover the nephrologist’s monthly management of ESRD patients. The correct code depends on the number of documented face-to-face visits during the calendar month and the dialysis setting:
| CPT Code | Setting | Face-to-Face Visits |
|---|---|---|
| 90960 | Outpatient dialysis | 4 or more visits per month |
| 90961 | Outpatient dialysis | 2 to 3 visits per month |
| 90962 | Outpatient dialysis | 1 visit per month |
| 90963 | Home dialysis | Full month |
| 90966 | Home dialysis | Less than full month |
The highest-value code, 90960, requires documentation of at least four face-to-face visits. Billing 90960 when only two or three visits are documented is a common upcoding error that triggers audits and recoupment demands from Medicare.
Dialysis Procedure Codes
These codes cover the actual dialysis treatments and are separate from the MCP codes:
- 90935 – Hemodialysis, single evaluation by a physician
- 90937 – Hemodialysis, repeated evaluation by a physician
- 90945 – Peritoneal dialysis, single evaluation
- 90947 – Peritoneal dialysis, repeated evaluation
A critical rule: dialysis procedure codes cannot be billed separately when the service falls within the MCP bundle for that month. Billing 90935 or 90937 for services already included in the monthly capitation creates an overpayment liability and puts your practice at risk for an OIG audit.
See how AMS Solutions helps over 25 medical specialties including nephrology with accurate, compliant billing.
CKD and General Nephrology Codes
Patients with chronic kidney disease who are not yet on dialysis bill under standard E/M codes (99202-99215 for office visits). The key requirement is ICD-10 specificity. Using the correct CKD stage code matters:
- N18.1 – CKD, Stage 1
- N18.2 – CKD, Stage 2
- N18.30/N18.31 – CKD, Stage 3 (with sub-stage specificity now required)
- N18.4 – CKD, Stage 4
- N18.5 – CKD, Stage 5
- N18.6 – ESRD
Payers are enforcing ICD-10 specificity with increasing consistency. Submitting N18.3 without the sub-stage designation (N18.30 or N18.31) leads to claim rejections that could have been avoided with proper coding at the point of service.
What Are the Most Common Nephrology Billing Errors?
Nephrology practices lose revenue from a predictable set of billing mistakes. Understanding these errors is the first step toward preventing them.
1. Wrong MCP Code Selection
This is the most frequent and most costly mistake. Billing 90960 (4+ visits) when the chart only documents three visits means the practice submitted a higher code than the documentation supports. Medicare tracks MCP billing patterns against peer group averages. Practices with unusually high 90960 rates receive documentation requests, and the defense is in the chart, not the claim.
2. Bundling Violations
The ESRD monthly capitation bundles certain services together. Billing separately for services already included in the MCP generates overpayment liability. CMS and the OIG actively audit dialysis-related unbundling. Practices with inconsistent billing patterns across their patient panels face higher scrutiny.
3. Inpatient and Outpatient Overlap
When a dialysis patient is hospitalized during the month, outpatient MCP codes cannot overlap with inpatient stay dates. Practices without a system for tracking hospitalization dates routinely submit MCP claims that overlap with inpatient stays, resulting in denials and recoupment requests.
4. CKD Stage Coding Errors
Failing to update the ICD-10 code when a patient’s CKD stage progresses leads to mismatched diagnoses and claim rejections. This is a documentation workflow issue. If the physician notes a stage change in the chart but the billing team does not update the code, the claim goes out with outdated information.
5. Missed Separately Billable Services
Not all services during a dialysis visit are included in the ESRD bundle. Certain lab work, medications, and high-cost outlier services can be billed separately when properly documented. CMS provides high-cost outlier payments when there are unusual variations in the type or amount of medically necessary care. Practices that fail to track and bill for these separately billable items leave revenue on the table every month.
How the ESRD Prospective Payment System Affects Your Revenue
Medicare’s ESRD Prospective Payment System (PPS) bundles a defined set of services into a single per-treatment payment for dialysis facilities. For 2026, CMS finalized the ESRD PPS base rate at $281.71, reflecting a 2.1 percent increase from the 2025 rate. Total payments across approximately 7,600 ESRD facilities are projected to reach $16.8 billion.
What this means for your practice: every service included in the bundle cannot be billed separately. Understanding which services fall inside and outside the bundle is not optional. It is a billing requirement that directly affects your bottom line.
The ESRD PPS also includes adjustments for patient acuity, geographic location, and facility type. Practices that do not account for these adjustments in their billing workflows miss opportunities to capture the full reimbursement they are entitled to.
Why Outsourcing Nephrology Billing Makes Financial Sense
Running nephrology billing in-house requires staff who understand the MCP structure, bundling rules, Medicare ESRD requirements, and the differences between CKD and ESRD billing models. That level of expertise is difficult to hire and expensive to maintain, especially with ongoing regulatory changes.
Here are the practical reasons nephrology practices choose to outsource their billing:
- Lower denial rates. A billing team with nephrology experience catches MCP coding errors, bundling violations, and documentation gaps before claims go out the door.
- Faster payment cycles. Clean claims submitted correctly the first time get paid faster. Fewer denials mean less time spent on rework and appeals.
- Reduced audit risk. Accurate coding and documentation that aligns with CMS peer group benchmarks keeps your practice out of the audit spotlight.
- Cost savings on staffing. You eliminate the overhead of hiring, training, and retaining in-house billing specialists who may not have nephrology-specific knowledge.
- Better focus on patient care. When billing is handled by professionals who specialize in it, your clinical team can spend more time with patients instead of chasing claims.
Get a free billing consultation from AMS Solutions to see how much revenue your nephrology practice could recover.
What to Look for in a Nephrology Billing Company
Not every medical billing company can handle nephrology. The specialty’s unique billing structure means you need a partner with specific experience. Here is what to evaluate:
- Nephrology-specific experience. Ask how many nephrology and dialysis clients the company currently serves. General billing experience is not enough for ESRD monthly capitation and bundling compliance.
- Medicare ESRD expertise. Your billing partner should understand the ESRD PPS, MCP coding requirements, and CMS audit triggers inside and out.
- Transparent pricing. Look for a flat percentage fee on collections with no hidden charges. Avoid companies that add software fees, setup costs, or per-claim charges on top of their percentage.
- EHR compatibility. Your billing company should integrate with your existing electronic health record system, not force you to switch platforms.
- Dedicated account management. You should have a single point of contact who knows your practice, your patient mix, and your specific billing patterns.
- Credentialing support. Nephrology practices frequently need credentialing with Medicare, Medicaid, and commercial payers. A billing partner that handles credentialing alongside billing saves you time and prevents coverage gaps.
How AMS Solutions Supports Nephrology and Dialysis Centers
AMS Solutions has served medical practices across the United States since 1986. Founded by a group of physicians, the company brings clinical insight to the billing process that most billing companies cannot match.
For nephrology and dialysis centers specifically, AMS Solutions provides:
- Full revenue cycle management from charge entry through final payment collection, including insurance follow-up and denial appeals
- Dedicated billing specialists with experience in ESRD monthly capitation coding, dialysis procedure billing, and CKD staging requirements
- 100% U.S.-based operations with all staff working from domestic locations, addressing data security and communication concerns
- Integration with any EHR system, including compatibility with over 26 major platforms used in nephrology practices
- Transparent, percentage-based pricing with no hidden fees, no setup costs, and no software charges
- Provider credentialing with Medicare, Medicaid, Blue Cross Blue Shield, and commercial carriers
- Practice management consulting including compliance support, fee schedule analysis, and performance reporting
With nearly 40 years of experience and client relationships that span over 25 years, AMS Solutions has the track record to back up its promise of better collections and lower denials for nephrology practices.
Frequently Asked Questions
What CPT codes are used for ESRD monthly capitation billing?
The primary ESRD monthly capitation codes are 90960 through 90966. For outpatient dialysis, 90960 covers four or more face-to-face visits per month, 90961 covers two to three visits, and 90962 covers one visit. Home dialysis uses codes 90963 through 90966 depending on whether it is a full or partial month of service.
Why do nephrology practices have high claim denial rates?
Nephrology practices face higher denial rates because of the complexity of ESRD billing. Common denial triggers include incorrect MCP code selection based on visit count errors, bundling violations where services included in the monthly capitation are billed separately, and missing ICD-10 specificity for CKD staging. The monthly capitation structure creates more opportunities for coding errors than standard per-visit billing.
Can dialysis procedure codes be billed alongside monthly capitation?
Dialysis procedure codes such as 90935 and 90937 cannot be billed separately for services that fall within the MCP bundle for that month. Billing these codes for bundled services creates overpayment liability and audit exposure. However, certain services that fall outside the ESRD bundle, such as specific lab work and high-cost outlier treatments, can be billed separately with proper documentation.
How much does it cost to outsource nephrology billing?
Most reputable medical billing companies charge a flat percentage of collections, typically ranging from 4% to 10% depending on practice size and claim volume. AMS Solutions uses a transparent percentage-based fee structure with no hidden costs, no setup fees, and no software charges. To get a customized quote for your nephrology practice, request a free consultation.
What is the ESRD Prospective Payment System?
The ESRD Prospective Payment System (PPS) is Medicare’s bundled payment model for dialysis services. It pays a single per-treatment rate that covers a defined set of renal dialysis services including drugs, lab tests, and supplies. For 2026, the base rate is $281.71 per treatment. Services outside the bundle can be billed separately, but facilities must understand the bundle boundaries to avoid compliance issues.
Take the Next Step for Your Nephrology Practice
Nephrology billing does not have to drain your practice’s resources or put your revenue at risk. The right billing partner understands the MCP structure, keeps up with CMS regulatory changes, and catches errors before they become denials.
Contact AMS Solutions for a free consultation and let our nephrology billing specialists show you how we can increase your collections, reduce your denials, and keep your practice compliant. Call 866-973-2221 or request your customized pricing quote today.
