Summary & Overview

HCPCS G9931: CHA2DS2-VASc Low Risk Documentation

HCPCS Level II code G9931 denotes documentation of a CHA2DS2-VASc risk score indicating low stroke risk: 0 or 1 for men, and 0, 1, or 2 for women. The code captures a discrete clinical finding used in stroke-risk stratification for patients with atrial fibrillation and informs anticoagulation decision pathways. Nationally, standardized documentation of CHA2DS2-VASc supports quality measurement, care coordination, and risk-based treatment planning.

Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Coverage and billing practices for G9931 vary across payers; payers may use the code for quality reporting, population health workflows, or to support care management programs.

Readers will find an overview of the code's clinical role, common service settings, and the policy context that shapes its use. The publication summarizes how G9931 fits into clinical documentation workflows, highlights typical billing considerations, and outlines where data are available or absent. This material is intended to inform clinicians, billers, and policy stakeholders about the purpose and practical implications of capturing low CHA2DS2-VASc scores in the medical record using HCPCS Level II code G9931.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG9931HCPCS Level IICHA2DS2-VAScstroke riskatrial fibrillationrisk stratificationoutpatientquality measurement

Billing Code Overview

HCPCS Level II code G9931 documents the CHA2DS2-VASc risk score when the calculated score is 0 or 1 for men, or 0, 1, or 2 for women. This code represents a structured clinical assessment of stroke risk in patients with atrial fibrillation or other conditions where CHA2DS2-VASc scoring is appropriate.

Service type: Risk stratification / clinical risk assessment

Typical site of service: Outpatient clinic or ambulatory care setting, where clinicians perform chart review and clinical calculation of stroke risk as part of medical decision-making or care management.

Clinical & Coding Specifications

Clinical Context

A 68-year-old female patient with a history of paroxysmal atrial fibrillation presents to a cardiology clinic for anticoagulation assessment after recent cardiology referral. The clinician documents a focused history including age, heart failure history, hypertension, diabetes status, prior stroke or transient ischemic attack, vascular disease, and sex category to calculate the CHA2DS2‑VASc score. The clinical workflow includes verifying medical record problem list and prior imaging/lab results, reviewing medications, calculating and documenting the CHA2DS2‑VASc score in the chart, and recording that the score is 0, 1 (for men), or 0, 1, or 2 (for women) as appropriate. Typical site of service is outpatient cardiology or primary care clinic; the service is performed during an evaluation visit or anticoagulation management encounter. Common scenario: clinician documents a low-risk CHA2DS2‑VASc score to support decision-making about initiating or withholding long-term oral anticoagulation; documentation is entered into the EHR problem list, visit note, and billing record to support use of G9931.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural service	Use when documentation supports substantially greater work beyond typical documentation for score calculation or counseling.
`23`	Unusual anesthesia	Not typically used for this nonprocedural service; rarely applicable.
`52`	Reduced services	Use if the CHA2DS2‑VASc documentation was partially completed or limited by patient factors.
`53`	Discontinued procedure	Use if the visit was terminated before score documentation was completed.
`54`	Surgical care only	Not applicable for this evaluation/documentation service.
`55`	Postoperative management only	Not applicable for this outpatient risk-score documentation.
`56`	Preoperative management only	Use if score documentation was performed solely as preoperative risk assessment.
`62`	Two surgeons	Not applicable for this service.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery	Not applicable for this service.
`CO`	Payment adjustment for managed care plan	Use when the patient is covered by a specific managed care arrangement requiring this modifier per payer rules.
`CQ`	Registered nurse in ambulatory surgery center	Rarely applicable; not typical for this outpatient documentation.
`FX`	Modifier for specific payer billing requirements	Use only if a payer (e.g., Blue Cross Blue Shield plan) requires `FX` for certain documentation billing rules.
`FY`	Replaced by another modifier per payer rules	Use per payer-specific guidance when required.
`QK`	Medical direction of two, three, or four CRNAs	Not applicable for this service.
`QX`	CRNA service with medical direction by physician	Not applicable for this service.

Taxonomy Code	Specialty	Notes
207RC0000X	Cardiology	Cardiologists commonly calculate and document CHA2DS2‑VASc for atrial fibrillation management.
207RH0000X	Electrophysiology	Cardiac electrophysiologists evaluate stroke risk and anticoagulation strategy in AF patients.
208D00000X	Family Medicine	Primary care clinicians frequently perform risk scoring during routine visits.
207L00000X	Internal Medicine	Internists document CHA2DS2‑VASc when managing chronic atrial fibrillation and anticoagulation.
363A00000X	Nurse Practitioner	Advanced practice clinicians in outpatient settings commonly document the score.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I48.0`	Paroxysmal atrial fibrillation	Atrial fibrillation subtype commonly prompting CHA2DS2‑VASc scoring to assess stroke risk and need for anticoagulation.
`I48.1`	Persistent atrial fibrillation	Persistent AF patients require stroke-risk stratification with CHA2DS2‑VASc.
`I48.2`	Chronic atrial fibrillation	Chronic AF is an indication for routine CHA2DS2‑VASc assessment.
`I48.91`	Unspecified atrial fibrillation	When AF is documented without further classification, CHA2DS2‑VASc guides anticoagulation decisions.
`I63.9`	Cerebral infarction, unspecified	History of ischemic stroke or TIA increases CHA2DS2‑VASc score and is directly relevant to risk calculation.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`99213`	Office or other outpatient visit for the evaluation and management of an established patient, typically 15 minutes	Common visit code during which CHA2DS2‑VASc score is calculated and documented for anticoagulation decision-making.
`99214`	Office or other outpatient visit for the evaluation and management of an established patient, typically 25 minutes	Used when documentation includes expanded history, medical decision-making, and counseling related to stroke risk and anticoagulation.
`93797`	Ambulatory blood pressure monitoring, unattended (device record review) — (example related cardiovascular monitoring)	May be performed in the same episode of care for cardiovascular risk assessment; not directly the CHA2DS2‑VASc calculation but part of cardiovascular evaluation.
`93228`	External electrocardiographic recording up to 48 hours by continuous rhythm recording and storage (Holter)	Performed before or after risk assessment for arrhythmia characterization; supports overall AF management.
`99406`	Smoking and tobacco-use cessation counseling, intermediate, greater than 3 minutes up to 10 minutes	Often provided alongside stroke-risk counseling in cardiovascular preventive care visits.