Summary & Overview
HCPCS Level II C9601: Drug‑Eluting Coronary Stent, Additional Branch
HCPCS Level II code C9601 denotes the percutaneous transcatheter placement of drug‑eluting intracoronary stent(s) for an additional branch of a major coronary artery, performed with coronary angioplasty when applicable. This interventional cardiology procedure is integral to contemporary acute and elective coronary revascularization strategies and carries significance for procedure reporting, hospital outpatient billing, and quality measurement across the United States. Key national payers include Aetna, Blue Cross Blue Shield, Cigna Health, and UnitedHealthcare.
This publication provides clinicians, coding professionals, and reimbursement analysts with a concise reference covering clinical context, billing and coding relationships, and payer coverage considerations for HCPCS Level II code C9601. Readers will find an overview of how the code fits with primary stent and angioplasty procedure codes, typical sites of service, commonly paired ICD‑10 principal diagnoses that justify the procedure, and related CPT/HCPCS codes used in coronary interventions. The summary outlines practical elements for claim preparation, common modifiers used when reporting additional procedures, and where data was missing from the source input. The goal is to clarify code intent and mapping so stakeholders can align documentation and billing workflows with clinical practice and payer policies.
Billing Code Overview
HCPCS Level II code C9601 describes percutaneous transcatheter placement of drug‑eluting intracoronary stent(s), with coronary angioplasty when performed; each additional branch of a major coronary artery (list separately in addition to code for primary procedure). This procedure is an interventional cardiology service involving transcatheter stent placement to open narrowed coronary arteries and deploy drug‑eluting stents in additional branch vessels beyond the primary artery treated.
Typical sites of service include hospital outpatient settings, such as Ambulatory Surgical Centers or Outpatient Hospital departments. Common place of service codes for billing include Place of Service 19, 22, and 24.
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 68-year-old patient presenting to the hospital outpatient department with acute chest pain and evidence of myocardial ischemia on ECG and cardiac biomarkers is evaluated by an interventional cardiology team. Coronary angiography demonstrates a significant stenosis involving a main coronary artery with an additional affected branch. The clinical workflow includes initial assessment in the emergency or observation area, informed consent, preprocedural anticoagulation and antiplatelet planning, transport to the cardiac catheterization laboratory in the hospital outpatient setting or ambulatory surgical center (Place of Service 19/22/24), coronary angiography to define anatomy, and performance of percutaneous transcatheter placement of a drug‑eluting intracoronary stent for the primary lesion. HCPCS Level II code C9601 is reported in addition to the primary stent placement code to account for the additional branch treated. Documentation includes indication (for example, unstable angina or acute myocardial infarction), vessel(s) treated, number and type of stents, adjunctive angioplasty, complications, and device implant logs.
Coding Specifications
Modifier 26 - Professional Component
- Use when reporting the professional interpretation or physician work component separate from the technical services. Applies if the physician bills separately for the professional component of the procedure.
Modifier 59 - Distinct Procedural Service
- Use when the service or procedure is distinct or independent from other services performed on the same day, such as a separate branch intervention reported in addition to the primary stent procedure. Use based on documentation that supports separate and distinct procedural work.
Associated Provider Taxonomies
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207RC0000X— Cardiovascular Disease Physician: Specialists in general cardiology who diagnose and manage coronary disease and refer for interventional procedures. -
207RI0011X— Interventional Cardiology Physician: Physicians who perform percutaneous coronary interventions, including stent placement and adjunctive angioplasty. -
207RG0300X— Geriatric Medicine Physician: Specialists providing care for older adults who may be involved in pre- or post-procedural management.
Common Coding Notes
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HCPCS Level II code
C9601is an add-on code and must be reported only in addition to the primary procedure code for intracoronary stent placement (for the first major coronary artery or branch). -
Report modifiers when documentation supports separate professional component billing or a distinct procedural service.
Related Diagnoses
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I20.0— Unstable angina- Clinical relevance: Indication for urgent coronary evaluation and possible percutaneous stent placement to relieve ischemia.
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I20.1— Angina pectoris with documented spasm- Clinical relevance: May prompt coronary assessment; stenting may be considered if fixed obstructive lesions are identified.
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I20.81— Angina pectoris with coronary microvascular dysfunction- Clinical relevance: Primarily a microvascular process; PCI with stent placement is relevant if concomitant epicardial obstructive lesions are found.
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I20.89— Other forms of angina pectoris- Clinical relevance: Broad angina diagnoses that can lead to coronary angiography and intervention when obstructive disease is present.
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I20.9— Angina pectoris, unspecified- Clinical relevance: Non‑specific angina diagnosis that may result in diagnostic angiography and percutaneous intervention if indicated.
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I21.01— ST elevation (STEMI) myocardial infarction involving left main coronary artery- Clinical relevance: STEMI is an acute indication for emergent PCI and stent placement when suitable.
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I21.02— ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery- Clinical relevance: Acute STEMI intervention frequently involves urgent stenting of the culprit lesion.
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I21.09— ST elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall- Clinical relevance: Similar acute indication for PCI and stent placement.
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I21.11— ST elevation (STEMI) myocardial infarction involving right coronary artery- Clinical relevance: Culprit lesion PCI with stent placement is standard care for reperfusion.
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I21.19— ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall- Clinical relevance: Indicates site-specific STEMI for which PCI and stenting may be performed.
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I21.21— ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery- Clinical relevance: Acute PCI with stenting may be performed for the culprit lesion.
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I21.29— ST elevation (STEMI) myocardial infarction involving other sites- Clinical relevance: STEMI involving other sites where urgent PCI and stenting are considered.
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I21.3— ST elevation (STEMI) myocardial infarction of unspecified site- Clinical relevance: Acute MI diagnosis where PCI with stent placement may be indicated.
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I21.4— Non‑ST elevation (NSTEMI) myocardial infarction- Clinical relevance: NSTEMI often leads to invasive evaluation with possible PCI and stenting based on anatomy and risk.
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I21.9— Acute myocardial infarction, unspecified- Clinical relevance: Acute MI diagnosis that may be managed with PCI and stent placement depending on clinical and angiographic findings.
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I21.A1— Myocardial infarction type 2- Clinical relevance: Type 2 MI is due to supply–demand mismatch; stenting is relevant only if concurrent obstructive coronary disease is identified as a cause.
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I21.A9— Other myocardial infarction type- Clinical relevance: Other MI types where coronary angiography and potential stent placement may be performed depending on etiology.
Related Codes
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92928— Percutaneous transcatheter placement of intracoronary stent(s), with coronary angioplasty when performed; single major coronary artery or branch- This is the primary procedure code for stent placement in a single major coronary artery or branch. HCPCS Level II code
C9601is reported in addition to the primary stent code to indicate each additional branch treated.
- This is the primary procedure code for stent placement in a single major coronary artery or branch. HCPCS Level II code
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93458— Catheter placement in coronary artery(s) for coronary angiography- Performed earlier in the workflow to visualize coronary anatomy; often precedes stent placement and guides selection of target lesions.
93458is typically performed in the same catheterization encounter.
- Performed earlier in the workflow to visualize coronary anatomy; often precedes stent placement and guides selection of target lesions.
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92920— Percutaneous transluminal coronary angioplasty; single major coronary artery or branch- Represents balloon angioplasty without stent placement or as part of lesion preparation. May be reported when angioplasty is performed distinct from stent placement; frequently performed in the same procedural session.
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93571— Intravascular Doppler velocity and/or pressure derived coronary flow reserve measurement- An adjunctive intracoronary physiological assessment that can be performed to evaluate lesion significance and guide decision-making for stenting. May be used during the same catheterization procedure.
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Clinical Use Relationships
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92928is the primary code for stent placement; HCPCS Level II codeC9601is an add-on for each additional branch beyond the first and is commonly billed together with92928. -
93458commonly precedes92928or92920during diagnostic angiography. -
92920may be an alternative or adjunct to stent codes when angioplasty alone is performed. -
93571is an adjunctive test and may be billed alongside angiography and intervention when performed.
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National Reimbursement Benchmarks
National commercial mean rates for HCPCS Level II code C9601 are materially higher than the Medicare benchmark: BUCA (the commercial average) has a mean rate of $2,671.60 compared with Medicare at $0.00 in the provided input. Among named commercial payers, UnitedHealthcare posts the highest mean at $4,810.37 while Cigna Health reports the lowest mean at $525.85.
Rate dispersion (P75 minus P25) varies substantially by payer. Blue Cross Blue Shield shows the widest spread (P75 $4,512.50 minus P25 $0.00 = $4,512.50), followed by UnitedHealthcare (P75 $2,337.00 minus P25 $171.00 = $2,166.00). Cigna Health is the tightest (P75 $85.00 minus P25 $71.25 = $13.75). The table and chart below present the full breakdown.
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