Billing Compliance Auditor

Overview

Internal billing audits are a core component of an effective compliance program as recommended by HHS OIG. This skill provides methodology for conducting chart audits, identifying coding errors, and implementing corrective actions to ensure compliant billing practices.

Why Audit

OIG COMPLIANCE PROGRAM GUIDANCE:
"Auditing and monitoring... should be ongoing to evaluate whether 
the compliance program elements have been implemented effectively 
and are working as designed."

RISKS OF NOT AUDITING:
- False Claims Act liability
- Overpayment/refund obligations (60-day rule)
- Exclusion from federal programs
- Civil monetary penalties
- Reputational damage

Audit Program Structure

┌─────────────────────────────────────────────────────────────────┐
│                    AUDIT PROGRAM COMPONENTS                     │
├─────────────────────────────────────────────────────────────────┤
│                                                                 │
│  PROSPECTIVE         CONCURRENT         RETROSPECTIVE          │
│  ─────────────       ──────────         ─────────────          │
│  Pre-billing         Real-time          Post-payment           │
│  review              edits              audits                  │
│                                                                 │
│  Catch errors        Prevent claim      Identify patterns      │
│  before billing      submission         and systemic issues    │
│                      errors                                     │
│                                                                 │
└─────────────────────────────────────────────────────────────────┘

Audit Types

1. E/M Leveling Audit

Focus: Evaluation & Management code selection accuracy

2021+ E/M Guidelines (MDM-Based):

Time-Based Selection:

2. Modifier Audit

Focus: Appropriate use of modifiers

High-Risk Modifier Combinations:

• 25 + procedure on same day
• 59/XE/XS/XP/XU on same-day services
• Multiple units of same procedure

3. Medical Necessity Audit

Focus: Does diagnosis support the service?

MEDICAL NECESSITY TEST:
1. Is the diagnosis documented in the record?
2. Does the diagnosis justify the service ordered?
3. Is the service reasonable for the condition?
4. Does documentation support the severity/need?

Common Medical Necessity Issues:

4. Documentation Audit

Focus: Does the chart support the code?

Documentation Requirements:

Audit Methodology

Sample Selection

Sample Size Guidelines:

Selection Methods:

Audit Scoring

Per-Chart Scoring:

CHART AUDIT SCORECARD
─────────────────────
Chart #: {number}
DOS: {date}
Provider: {name}
Billed Code: {code}
Auditor: {name}
Audit Date: {date}

CODING ASSESSMENT:
┌──────────────────────┬─────────┬──────────┬───────────┐
│ Element              │ Correct │ Error    │ Notes     │
├──────────────────────┼─────────┼──────────┼───────────┤
│ E/M Level            │ □       │ □ Over/Under │         │
│ Diagnosis Coding     │ □       │ □        │           │
│ Procedure Coding     │ □       │ □        │           │
│ Modifier Use         │ □       │ □        │           │
│ Medical Necessity    │ □       │ □        │           │
│ Documentation        │ □       │ □        │           │
└──────────────────────┴─────────┴──────────┴───────────┘

AUDITOR RECOMMENDATION:
□ No change
□ Upcode to: {code}
□ Downcode to: {code}
□ Add modifier: {modifier}
□ Remove modifier: {modifier}
□ Change diagnosis to: {code}
□ Cannot bill - insufficient documentation

FINANCIAL IMPACT: ${amount}

Error Classification

Error Rate Calculation

ERROR RATE = (Charts with Errors / Total Charts Audited) × 100

BENCHMARKS:
- <5% error rate: Acceptable
- 5-10% error rate: Needs improvement
- >10% error rate: Immediate corrective action required

FINANCIAL ERROR RATE:
= (Total $ Impact of Errors / Total $ Audited) × 100

Audit Workflow

Step 1: Plan the Audit

AUDIT PLAN
──────────
Audit Period: {date range}
Audit Type: {E/M / Modifier / Medical Necessity / Comprehensive}
Sample Size: {number}
Selection Method: {random / targeted / provider-specific}
Focus Areas: {specific concerns}
Auditor(s): {names}
Timeline: {start - complete dates}

Step 2: Pull Sample

SAMPLE SELECTION CRITERIA:
□ DOS range: {start} to {end}
□ Provider(s): {all / specific}
□ Code range: {if targeted}
□ Payer(s): {all / specific}
□ Exclusions: {if any}

DOCUMENT:
- How sample was selected
- Why this method chosen
- Claims included (list)

Step 3: Conduct Review

For each chart:

1. REVIEW DOCUMENTATION
   - Read clinical notes
   - Review orders, results
   - Check for required elements

2. DETERMINE SUPPORTED LEVEL
   - Apply E/M guidelines (MDM or time)
   - Verify modifier appropriateness
   - Confirm medical necessity

3. COMPARE TO BILLED
   - Match supported vs. billed
   - Identify discrepancies
   - Calculate financial impact

4. DOCUMENT FINDINGS
   - Complete audit scorecard
   - Note specific deficiencies
   - Recommend corrective action

Step 4: Analyze Results

AUDIT SUMMARY REPORT
────────────────────
Audit Period: {dates}
Charts Reviewed: {number}
Auditor: {name}

RESULTS:
┌────────────────────┬────────┬────────────┐
│ Category           │ Count  │ Percentage │
├────────────────────┼────────┼────────────┤
│ Correct as billed  │        │            │
│ Overcoded          │        │            │
│ Undercoded         │        │            │
│ Documentation issue│        │            │
│ Medical necessity  │        │            │
│ Modifier error     │        │            │
└────────────────────┴────────┴────────────┘

OVERALL ERROR RATE: {x}%
FINANCIAL IMPACT: ${amount}

TOP ISSUES IDENTIFIED:
1. {issue}
2. {issue}
3. {issue}

RECOMMENDATIONS:
1. {recommendation}
2. {recommendation}

Step 5: Corrective Action

Step 6: Document and Report

REQUIRED DOCUMENTATION:
□ Audit plan
□ Sample selection methodology
□ Individual chart scorecards
□ Summary report
□ Corrective action plan
□ Follow-up audit results (if applicable)

REPORTING:
□ Report to compliance officer/committee
□ Track trends over time
□ Benchmark against prior periods
□ Document corrective actions taken

Overpayment Handling

60-Day Rule (42 CFR § 401.305)

WHEN OVERPAYMENT IDENTIFIED:
1. IDENTIFY: When you have (or should have) actual knowledge
2. QUANTIFY: Determine the amount
3. REPORT: Notify payer
4. RETURN: Refund the overpayment

TIMELINE: Must report and return within 60 days of identification

FAILURE TO COMPLY = potential False Claims Act liability

Overpayment Workflow

OVERPAYMENT IDENTIFIED
        │
        ▼
┌───────────────────┐
│ Document finding  │
│ Date identified   │
│ Amount            │
│ Root cause        │
└─────────┬─────────┘
          │
          ▼
┌───────────────────┐
│ Quantify impact   │
│ Same error in     │
│ other claims?     │
└─────────┬─────────┘
          │
          ▼
┌───────────────────┐
│ Voluntary refund  │
│ to payer within   │
│ 60 days           │
└─────────┬─────────┘
          │
          ▼
┌───────────────────┐
│ Corrective action │
│ to prevent        │
│ recurrence        │
└───────────────────┘

High-Risk Areas to Monitor

OIG Work Plan Focus Areas

Red Flags

Audit Schedule

Resources

references/

• em-guidelines-2021.md — Current E/M documentation guidelines
• modifier-reference.md — Complete modifier guide with examples
• audit-scorecard-template.md — Fillable audit scorecard
• oig-risk-areas.md — Current OIG Work Plan focus areas

scripts/

• error-rate-calculator.py — Calculates audit metrics
• sample-selector.py — Random sample selection tool

assets/

• audit-report-template.docx — Audit summary report template
• corrective-action-plan.docx — CAP template