Nephrology Billing Compliance & Regulatory Updates (CMS, Medicare)
- Sirius solutions global
- 18 hours ago
- 7 min read
CMS Changed the Rules. Most Nephrology Practices Are Still Billing Under the Old Ones. That is not an exaggeration. It is a pattern.
Every year, CMS updates the Medicare Physician Fee Schedule, modifies ESRD bundling policies, adjusts the capitation payment structure, and issues compliance guidance that directly affects how nephrology services should be coded, documented, and billed. And every year, a significant portion of nephrology practices enter the new year billing under the previous year's rules because nobody in the building had time to read the Federal Register, and the billing vendor sent an email that nobody acted on.
The consequences are not abstract. They show up as denied claims, reduced reimbursements, and in the worst cases, post-payment audits that reach back 18 to 36 months and generate recoupment demands against revenue the practice has already spent.
Compliance is not optional in nephrology billing. It is the floor. The practices treating it as a once-a-year checkbox are one audit away from a financial event they were not prepared for.
This guide covers the 2026 CMS and Medicare regulatory landscape specifically for nephrology, what changed, what the compliance risks are, and what a practice needs to have in place to bill correctly and defensibly.
Before diving into the 2026 updates, it is worth mapping the regulatory terrain because nephrology operates under more overlapping compliance obligations than most specialties, and understanding which rule governs which service determines how billing errors turn into audit findings.
CMS and the Medicare Physician Fee Schedule
The Medicare Physician Fee Schedule (MPFS) governs reimbursement for nephrology services billed under Part B, proposed in July, finalized in November, effective January 1. For nephrology it covers: outpatient E/M visits (99202–99215), ESRD monthly capitation (90951–90966), kidney care planning services, chronic care management, transitional care management (99495, 99496), and procedures including kidney biopsy (50200) and dialysis access interventions.
The ESRD PPS and the Bundling Boundary
The ESRD Prospective Payment System governs the composite rate paid to dialysis facilities and defines what is bundled into that rate versus what the treating nephrologist can bill separately. This boundary shifts when CMS updates the bundle. When a previously separately billable service moves into the bundle, practices that do not update their protocols immediately start generating improper claims, ones that pay initially on some payers, get flagged on audit, and result in recoupment.
The OIG Work Plan
The HHS Office of Inspector General publishes an annual Work Plan identifying services under active audit focus. Nephrology has appeared repeatedly, specifically around ESRD monthly capitation payments, separately billed dialysis encounter services, and E/M medical necessity in CKD management.
"An OIG Work Plan entry is not a threat. It is a published list of what auditors are already looking at. Nephrology practices that ignore it are not being bold. They are being uninformed."
E/M Coding — The 2021 Changes Still Not Fully Implemented
The 2021 E/M coding revisions eliminated the history and physical exam as drivers of visit level, replacing them with Medical Decision Making (MDM) or total time. Four years later, nephrology practices are still miscoding under the old framework, particularly defaulting to 99213 and 99214 when MDM complexity consistently supports 99214 and 99215.
For nephrology, MDM drivers of higher visit levels:
Problem complexity — CKD with hypertension, diabetes, anemia, and secondary hyperparathyroidism qualifies as high complexity
Data complexity — lab panel review, independent imaging interpretation, specialist coordination each contribute data points
Risk — ESA dosing, phosphate binders, and transplant immunosuppressants qualify as high-risk prescription management under MDM
The practice defaulted to 99213 on a CKD Stage 4 visit because "that is what we usually bill" is leaving documented, defensible revenue behind and creating a coding record that misrepresents clinical complexity.
2026 ESRD Bundling Updates
CMS updates the ESRD bundle composition periodically. For 2026, practices should confirm the current bundling status of:
Still separately billable under most payer policies:
Unrelated E/M visits with Modifier 25 (separately diagnosable condition not related to ESRD)
Hospital visits for acute conditions in ESRD patients
Kidney biopsy (50200) and related pathology
Vascular access procedures — AV fistula creation (36821), AV graft placement (36830), thrombectomy, and angioplasty for dialysis access
Transitional care management (99495, 99496) within 30 days of discharge
Verify before billing:
Injectable medications — some previously separately billable drugs may have shifted into the 2026 ESRD bundle
Home dialysis supply and equipment billing boundaries — verify per payer
Telehealth ESRD management visits — coverage rules continue evolving post-PHE
Kidney Care Choices (KCC) Model
CMS continues advancing the KCC model for CKD Stage 4, Stage 5, and ESRD patients. For practices already participating, compliance considerations include: attribution rules that must be supported by billing documentation, quality measure documentation required in the clinical record (not just the billing system), and tracking the overlap between KCC enhanced payments and separately billed services to avoid duplicate payment issues.
Practices not currently in KCC should understand the compliance framework now. CMS is moving kidney care toward value-based payment, and the transition is easier when the documentation infrastructure is already in place.
These are not hypothetical risks. They are active audit targets, services and billing patterns that CMS Recovery Audit Contractors, Zone Program Integrity Contractors, and MACs are specifically reviewing in nephrology practices.
① Monthly Capitation Overpayment
ESRD capitation codes (90951–90966) are billed based on face-to-face physician visit count per month and patient age. The compliance risk: billing a 4-visit code when the documentation supports only 2 or 3.
Overpayment findings here are among the most common nephrology audit outcomes, not from intentional falsification, but because the billing workflow does not verify visit count against code selection before submission.
The fix: A monthly reconciliation that pulls documented face-to-face counts per patient before any capitation code is selected. Every patient. Every month.
② Separately Billed Services That Are Actually Bundled
Billing a bundled service as a separate claim is an improper payment whether or not the payer catches it initially. Some payers pay and claw back on audits. Medicare rarely pays them at all.
Risk is highest when: the billing team uses a prior-year fee schedule not updated for bundle changes; a new service or drug is added without checking bundling status; or mid-level providers bill ESRD patients for services already covered by the managing nephrologist's monthly capitation.
③ Missing or Non-Compliant Face-to-Face Documentation
Medicare requires each face-to-face visit for capitation billing to be distinguishable from non-face-to-face encounters in the documentation. Phone calls, portal messages, and indirect coordination do not count even when the nephrologist is actively managing the patient.
Audit findings here reach back multiple months, with recoupment calculated on the difference between the code billed and the visit count the documentation actually supports.
④ Telehealth Billing Errors Post-PHE
PHE-era telehealth expansions for ESRD patients have been modified, partially extended, or expired. The 2026 billing rules do not match 2022 rules and many practices are still billing under the expanded policies.
Common errors: billing telehealth at full in-person rates without correct modifiers, using POS 10 (patient home) when ESRD telehealth originating site rules are more restrictive, and billing services that are no longer covered under current telehealth authority.
⑤ Incident-To Billing Without Supervision Compliance
Many nephrology practices use NPs and PAs billed incident-to Medicare, at 100% of the physician fee schedule rather than the 85% APP rate. The compliance requirements are specific and frequently violated:
Direct supervision required — physician physically present in the office suite, not available by phone
Physician must have personally established the plan of care
New patients and new problems cannot be billed incident-to — direct physician involvement required
Incident-to violations are a consistent OIG audit target and have produced significant recoupment demands against practices that billed APP services at the physician rate without meeting the supervision requirements.
Compliance is not a separate function from billing. It is embedded in the billing workflow at every stage or it is not compliance at all.
The practice running this workflow at every stage is not just billing correctly. It is building a documentation record that survives the audit which means that if a RAC or ZPIC review lands on the practice, the response is a file pull, not a crisis.
Billing compliance is typically framed as a defensive function. That framing misses half the value.
The documentation specificity that protects against audit findings is the same documentation that supports higher E/M levels, correctly coded capitation, and defensible separate service billing. Compliance and revenue optimization are not competing priorities. They are the same work, done correctly.
A nephrology practice with a current compliance posture typically collects 10–14% more revenue than one billing loosely under outdated rules, while simultaneously reducing audit exposure.
"The practices that perform well on audit are not the ones who cleaned up before the auditor arrived. They are the ones who built the correct workflow and ran it every month — so when the request for records came, the response was a routine file pull, not a panic."
Regulatory updates do not wait for convenient timing. CMS final rules published in November. They take effect January 1. Practices that are not implementing changes before the calendar flips are already non-compliant on day one of the new year.
At Sirius Solutions Global, nephrology compliance is a continuous workflow — not an annual update email. Every claim review, capitation reconciliation, incident-to check, and documentation audit runs against current CMS standards.
When CMS issues an ESRD bundle change, our nephrology clients know before it affects a claim. When OIG adds a nephrology service to the Work Plan, we assess every client's billing patterns for that service before it becomes an audit finding.
Nephrology practices working with Sirius Solutions Global get:
Annual billing compliance audit against current CMS and OIG standards
Monthly capitation reconciliation, every patient, every month, as standard workflow
Real-time ESRD bundle status updates as CMS modifies policies
Incident-to compliance review on every APP-delivered service
E/M coding accuracy review against current MDM standards
We assess your current billing against 2026 CMS standards, identify the specific compliance risks in your practice's claims patterns, and show you what a correctly built nephrology revenue cycle looks like.
