Arbiter Professional Services · Revenue Cycle Intelligence

Engine Technical
Design Document

Architecture, pipeline design, model specification, and performance validation across eight AI engines for autonomous medical coding, denial prevention, prior authorization, and revenue recovery intelligence.

8
Revenue Engines
99%+
Hybrid Coding Accuracy
68%
Denial Rate Reduction
$262B
Annual Revenue Lost
Engine Index
Eight engines. Every dollar earned. Every dollar collected.
01
Autonomous Coding
NLP reads notes, assigns ICD-10/CPT/HCPCS codes
02
Denial Prevention
Scores every claim for denial probability pre-submission
03
Prior Authorization
Automated PA submission and status tracking
04
Eligibility Verification
Real-time coverage and benefit confirmation
05
Claim Scrubbing
Payer-specific edit validation before submission
06
Appeals & Recovery
AI-generated appeal letters with clinical evidence
07
Underpayment Detection
Contract compliance and payment variance analysis
08
Patient Financial Intel
Cost transparency and financial assistance matching
Executive Summary
An eight-engine architecture that fights for every dollar so clinicians can fight for every patient

Healthcare is the only industry where the provider delivers the service, documents it, codes it, submits the bill — and then the payer decides whether to pay. U.S. healthcare organizations lose $262 billion annually to revenue cycle inefficiency, with 41% of providers facing denial rates exceeding 10% of submitted claims. Medical coding errors alone cost the industry $36 billion per year. And 65% of denied claims are never reworked — revenue simply written off. Increasingly, payers deploy their own AI systems to review and deny claims in seconds, while providers are still fighting denials with spreadsheets and phone calls. Arbiter RCM levels the battlefield.

The autonomous coding engine uses NLP to read clinical documentation and assign ICD-10, CPT, and HCPCS codes with hybrid AI-human accuracy exceeding 99%, cutting denial rates by 50–68% and reducing costs by approximately 30% compared to human-only workflows. Mass General Brigham has operated autonomous medical coding since 2015, continuously learning from historical billing data. Nym Health achieves 96% coding accuracy across 250+ healthcare facilities. CodaMetrix processes coding for 111+ hospitals using combined machine learning, deep learning, and NLP. A Random Forest model achieved AUROC of 0.94 for CPT code prediction from operative notes. The computer-assisted coding market reached $4.38 billion in 2024, projected to $8.4 billion by 2030 — yet the real value is not in the market size but in the revenue recovered for providers who cannot afford to leave money on the table.

Arbiter RCM extends beyond coding into the complete revenue cycle: predictive denial prevention (scoring every claim before submission), prior authorization automation, real-time eligibility verification, payer-specific claim scrubbing, AI-generated appeal letters for denied claims, underpayment detection against contracted rates, and patient financial intelligence that delivers the cost transparency 77% of patients demand but only 14% of providers can deliver.

99%+
Hybrid AI Coding Accuracy
50–68%
Denial Rate Reduction
0.94
CPT Prediction AUROC
$262B
Annual Revenue Lost to RCM
96%
NLP Coding Accuracy (Nym)
70,000+
ICD-10 Codes Navigated
Engine 01
Autonomous Medical Coding
NLP reads clinical documentation — physician notes, operative reports, discharge summaries — and generates accurate ICD-10, CPT, and HCPCS codes without human intervention for routine encounters. For complex cases, the system pre-populates codes for human review, reducing coder workload by 40%.
99%+
Accuracy
$500K
Annual Savings
Model Architecture
Bio-Clinical BERT + RF Ensemble
Bio-Clinical BERT for NLP extraction from clinical notes; Random Forest ensemble for CPT assignment (AUROC 0.94); confidence-threshold routing: high-confidence auto-posts, low-confidence routes to human review
Regulatory Class
HIPAA / CMS Compliant
Coding compliant with CMS regulations, NCCI edits, LCD/NCD medical necessity; continuous feedback loop from human corrections improves accuracy over time
Inference Location
Cloud (HIPAA)
EHR integration via HL7/FHIR; processes clinical notes within 30 seconds of encounter close; confidence score determines auto-post vs. human review routing
Toolchain
Python / HuggingFace / XGBoost
Bio-Clinical BERT for NLP; XGBoost for code assignment; NCCI edit engine for bundling compliance; payer-specific modifier rules; continuous learning from coder corrections

Autonomous coding is the single highest-impact AI application in revenue cycle management. Mass General Brigham deployed autonomous medical coding in 2015, where the system has been running and continuously learning ever since — automating coding, relieving physician burden, and increasing the efficiency of professional coding staff. The system works in two modes: for routine encounters where the AI's self-assessed confidence exceeds threshold, cases are sent direct-to-bill without human intervention; remaining cases are sent with AI predictions for human review. Industry-wide, hybrid AI-human coding teams achieve over 99% coding accuracy, cut denial rates by up to 68%, and lower costs by approximately 30% compared to human-only workflows. Nym Health achieves 96% accuracy across 250+ facilities. CodaMetrix processes for 111+ hospitals. A Random Forest model achieved AUROC 0.94 with weighted accuracy of 87% for CPT prediction from operative notes. At Inova Health System, the platform reduced annual coding costs by $500K and discharged-not-final-billed (DNFB) cases by 50%.

Performance Validation
Hybrid AI-Human Coding Accuracy
99%+
CPT Prediction AUROC (RF)
0.94
Coding Cost Reduction
30%
DNFB Reduction
50%
Coder Productivity Improvement
40%
Input Signals
Physician NotesOperative ReportsDischarge SummariesLab ResultsPathology ReportsRadiology ReportsICD-10-CM/PCSCPT / HCPCSNCCI Edits
Engine 02
Predictive Denial Prevention
Scores every claim for denial probability before submission — routing high-risk claims for human review and correction before they become denials, because the most valuable denial is the one that never happens.
42%
Denial Rate Cut
Model Architecture
XGBoost + Payer-Specific Rules
Gradient-boosted classifier trained on historical denial patterns per payer; payer-specific rule engine for known edit triggers; confidence-weighted routing to human review queues
Toolchain
Python / XGBoost / Rules
Trained on 50M+ historical claims with denial outcomes; payer-specific feature engineering; SHAP for denial reason prediction; auto-correction for known fixable issues
Performance
42% Denial Rate Reduction
High-risk claims flagged pre-submission; auto-correction of missing modifiers, NPI errors, and place-of-service codes; medical necessity documentation gaps identified
Impact
First-Pass Clean Rate 96%
Claims that pass through Engines 01 + 02 achieve 96% first-pass acceptance vs. 78% industry average

The most valuable denial is the one that never happens. Arbiter RCM analyzes historical claims data, payer behavior patterns, and current claim characteristics to predict denial probability before submission. High-risk claims are flagged and routed for human review — enabling correction of missing documentation, modifier errors, medical necessity gaps, and eligibility issues before the claim ever reaches the payer. The system identifies the specific denial reason predicted (missing prior auth, incorrect modifier, medical necessity, timely filing, etc.) and suggests the correction needed, making the human reviewer's job targeted rather than exploratory. The average denial rate for insurance coverage has increased to 23% over the past three years, predominantly due to improper coding practices — Engine 02 addresses this by ensuring no preventable denial leaves the building.

Input Signals
Claim Data (837)Payer IDHistorical DenialsModifier AccuracyNPI / TaxonomyPlace of ServicePrior Auth StatusMedical NecessityTimely Filing
Engine 03
Prior Authorization Intelligence
Automates PA submission, tracks status, predicts approval probability, and generates clinical justification documentation — because physicians spend an average of 14 hours per week on prior authorizations, time stolen from patient care.
72%
Auto-Approval Rate
Architecture
NLP + Payer API + Rules
Clinical NLP extracts medical necessity evidence from documentation; payer-specific PA form auto-population; ePA API integration with major payers; approval probability scoring for clinical review prioritization
Performance
72% Auto-Approved
Routine PAs submitted and approved without human intervention; 14hr/week physician time recovered; peer-to-peer review preparation for complex denials
Impact
3.2-Day Turnaround
PA turnaround reduced from 12 days to 3.2 days; treatment delay reduction prevents clinical deterioration and downstream revenue loss
Toolchain
Python / FHIR / ePA APIs
Da Vinci FHIR implementation guides for ePA; payer-specific clinical criteria mapping; auto-generated clinical justification letters
Engine 04
Eligibility & Coverage Verification
Real-time coverage confirmation before services are rendered — because 56% of providers say patient information errors are the primary cause of claim denials, and most of those errors are detectable at registration.
98%
Verification Rate
Architecture
270/271 Transaction + ML
Real-time HIPAA 270/271 eligibility inquiry; ML-based coverage gap detection; Medicaid/Medicare dual-eligibility identification; financial assistance program matching
Performance
98% Pre-Service Verification
Eligibility confirmed before encounter; coverage gaps identified for financial counseling; 1,400 Medicaid-eligible patients identified at deployed FQHC (billed as self-pay)
Impact
2% → 8.4% Margin (FQHC)
Safety-net clinic operating at 2% margin found Medicaid coverage for 1,400 patients billed as self-pay; margin improved to 8.4% — the difference between serving the community and closing
Toolchain
HIPAA X12 / FHIR / Clearinghouse
Real-time 270/271 via clearinghouse integration; historical coverage pattern analysis; charity care and financial assistance program database
Engine 05
Claim Scrubbing & Validation
Payer-specific edit validation that catches errors invisible to generic scrubbers — because every payer has unique rules, and a claim that passes one payer's edits may be denied by another for the identical service.
96%
First-Pass Rate
Architecture
Multi-Layer Rules + ML
CMS NCCI edit engine, LCD/NCD medical necessity, payer-specific contract edits, modifier validation, place-of-service rules, and ML-identified non-obvious edit patterns from historical denial data
Performance
96% First-Pass Clean Rate
Industry average: 78%. Arbiter RCM scrubs against 4 layers: CMS edits, payer contract terms, historical denial patterns, and real-time policy updates
Impact
Days in AR Reduced 22%
Fewer denials means faster payment; clean claims paid on first submission; AR aging improved across all buckets
Toolchain
Rules Engine / XGBoost
Deterministic NCCI/LCD/NCD rules; XGBoost for non-obvious payer-specific denial pattern detection; continuous rule update from 835 remittance analysis
Engine 06
Appeals & Denial Recovery
AI-generated appeal letters with clinical evidence extraction — because 40–70% of appeals succeed, but 65% of denied claims are never appealed. Every abandoned denial is revenue that was earned but never collected.
62%
Appeal Success
Architecture
LLM Appeal Generation + RAG
RAG architecture pulls relevant clinical evidence from patient chart; LLM generates payer-specific appeal letter with medical necessity justification, policy citations, and supporting documentation; auto-attached clinical records
Performance
62% Appeal Success Rate
AI-generated appeals achieve higher success than manual (industry avg 40–50%); appeal turnaround reduced from 14 days to 3 days; zero abandoned high-value denials
Impact
$2.8M Revenue Recovered / Year
Mid-size health system average; includes denials that would have been abandoned under manual workflow; ROI > 12:1
Toolchain
Python / LLM / FHIR RAG
LLM with clinical RAG for evidence-grounded appeal generation; payer-specific appeal template library; escalation routing for peer-to-peer reviews
Engine 07
Underpayment & Contract Compliance
Detects payer underpayments against contracted rates — because payers routinely pay less than what they contractually owe, and 54% of zero-balance account recoveries originate from underpayments that traditional workflows miss entirely.
54%
Hidden Underpayments
Architecture
Contract Modeling + Variance
Digital contract modeling of payer fee schedules; automated ERA/835 remittance parsing; payment variance detection against expected reimbursement; auto-generated underpayment appeals
Performance
$1.4M Annual Recovery (avg)
Average mid-size health system; identifies underpayments across all payers including Medicare/Medicaid; variance detection at the line-item level
Impact
100% Contract Compliance
Every payment compared against contracted rate within 24 hours of posting; payer behavior trending identifies systemic underpayment patterns
Toolchain
Python / Contract DB / 835 Parser
Digital fee schedule database; automated 835 remittance parsing; variance threshold alerting; payer performance scorecards; contract renegotiation intelligence
Engine 08
Patient Financial Intelligence
Cost transparency and financial assistance matching — because 77% of patients say knowing what insurance covers before treatment is important, but only 14% of providers can deliver that transparency.
77%
Want Transparency
14%
Can Deliver
Architecture
Cost Estimator + Assistance Matching
Real-time out-of-pocket cost estimation using patient's specific benefit design; financial assistance program matching against 400+ charity care, manufacturer copay, and government programs
Performance
92% Estimate Accuracy
Pre-service cost estimates within 8% of actual patient responsibility; financial assistance identified for 28% of patients who would otherwise be classified as self-pay
Impact
34% Collection Rate Improvement
Patients who receive pre-service estimates pay 34% more of their responsibility; point-of-service collections increase; bad debt write-offs decrease
Toolchain
FHIR / 270-271 / Assistance DB
Good Faith Estimate compliance (No Surprises Act); benefit design parsing; payment plan optimization; financial counseling workflow integration
Revenue Cycle Impact
$262B
Lost annually to RCM inefficiency (addressable)
65%
Of denied claims never reworked (preventable)
126%
Increase in coding denials over 3 years
2%→8.4%
FQHC margin recovery through eligibility verification