Coding Accuracy Validator | Skills Pool
Coding Accuracy Validator Validate ICD-10-CM diagnosis and CPT/HCPCS procedure code accuracy against clinical documentation, NCCI edits, LCD/NCD policies, and coding guidelines. Use when auditing coded claims, validating code assignments before submission, performing coding compliance reviews, or training coders on accurate code selection.
Occupation Categories Code Quality Overview
Validate the accuracy of ICD-10-CM diagnosis codes and CPT/HCPCS procedure codes against clinical documentation, official coding guidelines, NCCI (National Correct Coding Initiative) edits, payer-specific policies, and medical necessity requirements. This skill supports coding compliance, reduces claim denials from coding errors, and ensures optimal reimbursement through accurate code capture.
When to Use
Auditing coded claims before submission for accuracy
Validating diagnosis-procedure code linkages (medical necessity)
Checking for NCCI edit violations (bundling/unbundling)
Reviewing coding specificity and compliance with Official Coding Guidelines
Performing retrospective coding audits for compliance programs
Supporting coder education with detailed code validation feedback
Input Description Format Assigned codes
Quick Install
Coding Accuracy Validator npx skillvault add writer/writer-skills-skills-coding-accuracy-validator-skill-md
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Updated Mar 2, 2026
Occupation ICD-10-CM and CPT/HCPCS codes with modifiers
Clinical documentation Encounter note supporting the codes Text or structured note
Encounter type Inpatient, outpatient, professional, facility Enum string
Provider specialty Specialty of the rendering provider String
Payer Payer for LCD/NCD validation String
Methodology
Step 1: ICD-10-CM Diagnosis Code Validation Validate each assigned diagnosis code:
Is the code at the highest level of specificity supported by documentation?
Are required 4th, 5th, 6th, and 7th characters present?
Is laterality captured where applicable?
Are episode-of-care characters correct (A=initial, D=subsequent, S=sequela)?
Are combination codes used where available (e.g., E11.65 for DM2 with hyperglycemia)?
Does the clinical note explicitly document the condition coded?
Is the diagnosis stated by the physician (or qualified provider)?
Are signs/symptoms coded only when no definitive diagnosis exists?
For inpatient: Is the principal diagnosis the condition established after study to be chiefly responsible for the admission?
Coding Guideline Compliance:
ICD-10-CM Official Guidelines for Coding and Reporting compliance
Chapter-specific guidelines (e.g., Chapter 4 endocrine, Chapter 9 circulatory)
Selection of principal diagnosis guidelines for inpatient
Present on admission (POA) indicator accuracy for inpatient claims
External cause codes where applicable (V, W, X, Y codes)
Step 2: CPT/HCPCS Procedure Code Validation Validate each assigned procedure code:
Does the CPT code description match the documented procedure or service?
Is the correct code range selected (e.g., excision vs. destruction vs. shaving)?
Are time-based codes supported by documented time?
For E/M codes: Does the MDM level match the documentation?
Are required modifiers present (25, 59, 76, 77, LT/RT, etc.)?
Is modifier 25 (significant, separately identifiable E/M) justified with documentation?
Are modifiers used correctly (not to bypass edits inappropriately)?
Are anatomic modifiers correct (LT/RT, F1-F9, T1-T9)?
Are units billed consistent with documentation?
For time-based services, do units match documented time (e.g., 97110 per 15-min increments)?
Does the frequency of service align with medical necessity?
Step 3: NCCI Edit Validation Check for National Correct Coding Initiative violations:
Identify code pairs where one procedure is a component of another
Verify if modifier bypass is permitted (modifier indicator 1 = modifier allowed)
Confirm documentation supports separate and distinct services when modifier used
Medically Unlikely Edits (MUEs):
Verify units billed do not exceed MUE limits for each CPT code
MUE adjudication: claim line (1), date of service (2), or per day (3)
If exceeding MUE, verify documentation supports the units
Add-on codes must be billed with the primary procedure
Verify the correct primary procedure is present
Add-on codes cannot be billed standalone
Step 4: Medical Necessity Linkage Validate diagnosis-procedure linkage:
Does the diagnosis code medically justify the procedure?
Check against LCD/NCD covered diagnoses lists
Verify the clinical scenario supports the service ordered
Flag procedures without supporting diagnosis justification
Frequency and Setting Appropriateness:
Is the service frequency within payer guidelines?
Is the place of service appropriate for the procedure?
Are duplicate services on the same date appropriately modified or justified?
Step 5: Validation Report Generation Produce the comprehensive validation report:
Severity Classifications:
CRITICAL: Code will likely result in denial, audit risk, or compliance violation
WARNING: Code may be questioned; additional documentation recommended
ADVISORY: Best practice suggestion for coding optimization
PASS: Code is accurate and well-supported
Output Specification validation_summary : total_codes_reviewed, critical_issues, warnings, advisories, passes, overall_accuracy_score (0-100%)
diagnosis_code_validation : for each ICD-10 code — code, description, validation_status, specificity_assessment, documentation_support (supported/partial/unsupported), guideline_compliance_issues, recommended_code (if different), rationale
procedure_code_validation : for each CPT/HCPCS code — code, description, validation_status, modifier_assessment, units_assessment, documentation_support, recommended_code (if different), rationale
ncci_edit_results : code_pair, edit_type (column1-column2/MUE/add-on), modifier_indicator, violation_status, recommendation
medical_necessity_linkage : procedure_code, linked_diagnosis, linkage_valid (yes/no), lcd_ncd_reference, coverage_status
compliance_risk_assessment : overall_risk_level (low/moderate/high), specific_risks, documentation_recommendations, coder_education_points
Analysis Framework
Common Coding Errors by Category Error Category Example Risk Level Upcoding E/M 99215 billed without supporting MDM Critical — compliance/fraud risk Undercoding E/M 99213 billed when documentation supports 99214 Warning — revenue loss Unbundling Billing component codes separately when a comprehensive code exists Critical — compliance risk Missing specificity E11.9 (DM2 unspecified) when complications documented Warning — may trigger query Wrong laterality Right knee procedure coded without RT modifier Critical — denial risk Missing modifier Two distinct E/M services without modifier 25 Critical — denial risk Diagnosis-procedure mismatch Screening mammography coded with breast cancer diagnosis Critical — medical necessity
E/M Code Level Validation (2021+ MDM-Based) E/M Level Problem Complexity Data Complexity Risk 99212/99202 Straightforward Minimal or none Minimal 99213/99203 Low Limited Low 99214/99204 Moderate Moderate Moderate 99215/99205 High Extensive High
Two of three MDM elements must meet the level billed.
Examples Input : Outpatient visit coded with 99214 (E/M moderate), ICD-10: E11.9 (DM2 unspecified), 83036 (HbA1c), 99214-25, 36415 (venipuncture).
E11.9 — WARNING: DM2 coded as unspecified. Note documents diabetic neuropathy and retinopathy. Recommend E11.40 (DM2 with diabetic neuropathy unspecified) and E11.319 (DM2 with unspecified diabetic retinopathy without macular edema) for full capture
99214 — PASS: MDM moderate level supported (multiple chronic conditions, medication management, prescription drug management risk)
99214-25 — PASS: Modifier 25 appropriate since separately identifiable E/M with lab draw
83036 — PASS: HbA1c medically necessary for DM2 monitoring, LCD covered
36415 — ADVISORY: Venipuncture is typically included in the office visit unless performed by a separate lab; verify billing arrangement
Guidelines
Code only what is documented — never assign codes based on clinical assumptionsSpecificity matters — always code to the highest level of specificity supported by documentationQuery before assuming — when documentation is ambiguous, issue a physician query rather than guessingFollow Official Guidelines — ICD-10-CM Official Guidelines are the authoritative referenceKeep NCCI edits current — CMS updates NCCI edits quarterly
Validation Checklist
HIPAA Compliance Notes
Coding validation involves access to clinical documentation containing PHI
Coding audit results must be stored securely with appropriate access controls
External coding auditors must operate under a BAA
Coding validation findings used for education should be de-identified
Maintain audit trails for all coding reviews for compliance program documentation
False Claims Act implications: knowingly submitting inaccurate codes constitutes potential fraud
When to Use