Summary & Overview

HCPCS G9798: AMI Discharge Between July 1 Prior Year and June 30 Measurement Year

HCPCS Level II code G9798 identifies discharges for acute myocardial infarction (AMI) that occur between July 1 of the year prior to the measurement period and June 30 of the measurement period. The code is used in national quality measurement and reporting frameworks to define the eligible AMI discharge cohort for performance assessment. Its consistent use matters for accurate denominator construction in measures tied to AMI care processes and outcomes.

Major national payers referenced in analyses typically include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. These payers use standardized discharge flags and quality reporting codes to align claims-based measurement across plans.

Readers will find benchmarks and reporting context for how G9798 is used to delineate measurement cohorts, summaries of payer coverage practices, and clinical context about why capturing the precise discharge window (July 1 to June 30) affects longitudinal quality measurement. The publication outlines policy considerations around claim-level coding for AMI discharges, the implications for performance measurement timing, and operational notes for mapping inpatient discharge records into quality reporting datasets. Data not available in the input is noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareG9798HCPCS Level IIacute myocardial infarctionAMI dischargequality measurementinpatient dischargeclaims codingperformance measurement

Billing Code Overview

HCPCS Level II code G9798 documents discharges for acute myocardial infarction (AMI) that occurred between July 1 of the year prior to the measurement period and June 30 of the measurement period. This code captures a cohort of AMI discharges for quality measurement and reporting purposes.

Service type: Quality measurement / discharge event tracking
Typical site of service: Inpatient hospital discharge

Data not available in the input for payers, associated taxonomies, ICD-10 diagnoses, related codes, and service line.

Clinical & Coding Specifications

Clinical Context

A typical patient is a 62-year-old male admitted to an acute care hospital with an ST-elevation myocardial infarction (STEMI) on March 10 of the measurement period. He receives emergent reperfusion therapy, cardiac monitoring, and inpatient cardiology care. After stabilization and completion of in-hospital treatment, he is discharged home on March 16 with prescriptions, discharge instructions, and follow-up cardiology appointments. The billing code G9798 is used to identify a discharge for acute myocardial infarction (AMI) that occurs between July 1 of the year prior to the measurement year and June 30 of the measurement year for quality reporting and population measurement programs. Typical workflow includes documentation of admission and discharge diagnoses, treatment summary, reconciliation of medications, cardiovascular secondary prevention counseling, and submission of the appropriate discharge code for administrative and reporting purposes.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when substantially greater work is performed beyond typical services documented in operative or procedure notes affecting billing for services around AMI care (rare for pure discharge reporting).
`23`	Unusual anesthesia	Use if unusual circumstances require general anesthesia for a procedure performed during AMI care (applies to interventional procedures related to AMI, not the discharge code itself).
`52`	Reduced services	Use when a planned service is partially reduced or not completed during an AMI hospitalization (e.g., abbreviated diagnostic testing).
`53`	Discontinued procedure	Use when an anticipated procedure is started but terminated due to patient condition during AMI care.
`54`	Surgical care only	Use when another clinician performs postoperative care after an AMI-related cardiac procedure.
`55`	Postoperative management only	Use when the billing clinician is responsible only for postoperative care following an AMI-related operation.
`56`	Preoperative management only	Use when the billing clinician provides only preoperative evaluation prior to an AMI-related procedure.
`62`	Two surgeons	Use when two surgeons work together as primary surgeons for a complex cardiac procedure during the AMI admission.
`AS`	Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery	Use when an advanced practice clinician assists in a procedure during the AMI admission.
`QX`	CRNA service furnished with CPT code for anesthesia services by a modifier QK-qualified CRNA	Use when a certified registered nurse anesthetist furnishes anesthesia in an AMI-related procedure requiring anesthesia.

Taxonomy Code	Specialty	Notes
207RC0000X	Cardiology	Cardiology physicians direct inpatient AMI management and determine discharge planning.
207RN0400X	Interventional Cardiology	Interventional cardiologists perform percutaneous coronary intervention during AMI admissions.
207RG0300X	Internal Medicine	Hospitalist and general internists provide inpatient medical management and coordinate discharge.
363L00000X	Critical Care Medicine	Intensivists manage critically ill AMI patients requiring ICU-level care.
208D00000X	Family Medicine	Family physicians may provide inpatient care and follow-up coordination for AMI discharges.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`I21.01`	ST elevation (STEMI) myocardial infarction of anterior wall	Represents an acute MI diagnosis commonly leading to an AMI hospitalization and subsequent discharge billed with `G9798`.
`I21.02`	ST elevation (STEMI) myocardial infarction of inferior wall	Another common acute MI presentation prompting inpatient care and discharge capture.
`I21.09`	ST elevation (STEMI) myocardial infarction of other sites	Captures STEMI locations relevant to AMI admissions within the measurement window.
`I21.3`	ST elevation (STEMI) myocardial infarction, unspecified site	Used when site is not specified but an AMI discharge is still reportable.
`I22.0`	Subsequent ST elevation (STEMI) myocardial infarction of anterior wall	Represents reinfarction during the same or subsequent admission within the reporting period; relevant to discharge reporting.
`I25.10`	Atherosclerotic heart disease of native coronary artery without angina pectoris	Chronic ischemic heart disease often present as comorbidity at AMI discharge and relevant to secondary prevention planning.
`I46.9`	Cardiac arrest, cause unspecified	May occur during AMI admission and affect in-hospital course and discharge documentation.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`92928`	Percutaneous transcatheter placement of intracoronary stent(s), with coronary angioplasty when performed; single major coronary artery or branch	Commonly performed during acute STEMI admissions prior to discharge when percutaneous coronary intervention is indicated.
`93458`	Catheter placement in coronary artery(ies) for coronary angiography, with left heart catheterization including intraprocedural injection(s) for selective coronary angiography and with coronary angiography when performed; with left ventriculography, when performed	Diagnostic coronary angiography performed during AMI admission to define coronary anatomy before revascularization and discharge planning.
`92920`	Percutaneous transluminal coronary angioplasty; single major coronary artery or branch	Performed during AMI management prior to discharge when balloon angioplasty is used for revascularization.
`99223`	Initial hospital care, typically 70 minutes or more	Hospitalist or cardiologist initial or complex inpatient evaluation code used at admission for AMI; relates to the inpatient episode that culminates in discharge coded by `G9798`.
`99238`	Hospital discharge day management; 30 minutes or less	Professional discharge services documented at the end of the AMI hospitalization; complements administrative reporting using `G9798` for discharge identification.
`99495`	Transitional care management services with communication within 2 business days and face-to-face visit within 14 calendar days, moderate complexity	Post-discharge transition services often billed after AMI discharge to support continuity of care and follow-up.