CPT C9603: ICD-10 codes that support medical necessity
These ICD-10-CM diagnoses support medical necessity for CPT C9603 under Medicare coverage policies (LCDs, NCDs, and Billing & Coding articles). Billing CPT C9603 with a diagnosis that isn't covered typically denies as CARC 50 — not medically necessary.
National approximation. Coverage varies by MAC and state — confirm against the specific LCD/NCD and article that applies to your jurisdiction and date of service.
| ICD-10 | Description |
|---|---|
| I20.0 | Unstable angina |
| I20.1 | Angina pectoris with documented spasm |
| I20.81 | Angina pectoris with coronary microvascular dysfunction |
| I20.89 | Other forms of angina pectoris |
| I20.9 | Angina pectoris, unspecified |
| I21.01 | ST elevation (STEMI) myocardial infarction involving left main coronary artery |
| I21.02 | ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery |
| I21.09 | ST elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall |
| I21.11 | ST elevation (STEMI) myocardial infarction involving right coronary artery |
| I21.19 | ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall |
| I21.21 | ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery |
| I21.29 | ST elevation (STEMI) myocardial infarction involving other sites |
| I21.3 | ST elevation (STEMI) myocardial infarction of unspecified site |
| I21.4 | Non-ST elevation (NSTEMI) myocardial infarction |
| I21.9 | Acute myocardial infarction, unspecified |
| I21.A1 | Myocardial infarction type 2 |
| I21.A9 | Other myocardial infarction type |
| I21.B | Myocardial infarction with coronary microvascular dysfunction |
| I22.0 | Subsequent ST elevation (STEMI) myocardial infarction of anterior wall |
| I22.1 | Subsequent ST elevation (STEMI) myocardial infarction of inferior wall |
| I22.2 | Subsequent non-ST elevation (NSTEMI) myocardial infarction |
| I22.8 | Subsequent ST elevation (STEMI) myocardial infarction of other sites |
| I22.9 | Subsequent ST elevation (STEMI) myocardial infarction of unspecified site |
| I24.0 | Acute coronary thrombosis not resulting in myocardial infarction |
| I24.1 | Dressler's syndrome |
| I24.81 | Acute coronary microvascular dysfunction |
| I24.89 | Other forms of acute ischemic heart disease |
| I24.9 | Acute ischemic heart disease, unspecified |
| I25.10 | Atherosclerotic heart disease of native coronary artery without angina pectoris |
| I25.110 | Atherosclerotic heart disease of native coronary artery with unstable angina pectoris |
| I25.111 | Atherosclerotic heart disease of native coronary artery with angina pectoris with documented spasm |
| I25.112 | Atherosclerotic heart disease of native coronary artery with refractory angina pectoris |
| I25.118 | Atherosclerotic heart disease of native coronary artery with other forms of angina pectoris |
| I25.119 | Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris |
| I25.3 | Aneurysm of heart |
| I25.41 | Coronary artery aneurysm |
| I25.42 | Coronary artery dissection |
| I25.5 | Ischemic cardiomyopathy |
| I25.6 | Silent myocardial ischemia |
| I25.700 | Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris |
| I25.701 | Atherosclerosis of coronary artery bypass graft(s), unspecified, with angina pectoris with documented spasm |
| I25.702 | Atherosclerosis of coronary artery bypass graft(s), unspecified, with refractory angina pectoris |
| I25.708 | Atherosclerosis of coronary artery bypass graft(s), unspecified, with other forms of angina pectoris |
| I25.709 | Atherosclerosis of coronary artery bypass graft(s), unspecified, with unspecified angina pectoris |
| I25.710 | Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris |
| I25.711 | Atherosclerosis of autologous vein coronary artery bypass graft(s) with angina pectoris with documented spasm |
| I25.712 | Atherosclerosis of autologous vein coronary artery bypass graft(s) with refractory angina pectoris |
| I25.718 | Atherosclerosis of autologous vein coronary artery bypass graft(s) with other forms of angina pectoris |
| I25.719 | Atherosclerosis of autologous vein coronary artery bypass graft(s) with unspecified angina pectoris |
| I25.720 | Atherosclerosis of autologous artery coronary artery bypass graft(s) with unstable angina pectoris |
| I25.721 | Atherosclerosis of autologous artery coronary artery bypass graft(s) with angina pectoris with documented spasm |
| I25.722 | Atherosclerosis of autologous artery coronary artery bypass graft(s) with refractory angina pectoris |
| I25.728 | Atherosclerosis of autologous artery coronary artery bypass graft(s) with other forms of angina pectoris |
| I25.729 | Atherosclerosis of autologous artery coronary artery bypass graft(s) with unspecified angina pectoris |
| I25.730 | Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unstable angina pectoris |
| I25.731 | Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with angina pectoris with documented spasm |
| I25.732 | Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with refractory angina pectoris |
| I25.738 | Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with other forms of angina pectoris |
| I25.739 | Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unspecified angina pectoris |
| I25.750 | Atherosclerosis of native coronary artery of transplanted heart with unstable angina |
| I25.751 | Atherosclerosis of native coronary artery of transplanted heart with angina pectoris with documented spasm |
| I25.752 | Atherosclerosis of native coronary artery of transplanted heart with refractory angina pectoris |
| I25.758 | Atherosclerosis of native coronary artery of transplanted heart with other forms of angina pectoris |
| I25.759 | Atherosclerosis of native coronary artery of transplanted heart with unspecified angina pectoris |
| I25.760 | Atherosclerosis of bypass graft of coronary artery of transplanted heart with unstable angina |
| I25.761 | Atherosclerosis of bypass graft of coronary artery of transplanted heart with angina pectoris with documented spasm |
| I25.762 | Atherosclerosis of bypass graft of coronary artery of transplanted heart with refractory angina pectoris |
| I25.768 | Atherosclerosis of bypass graft of coronary artery of transplanted heart with other forms of angina pectoris |
| I25.769 | Atherosclerosis of bypass graft of coronary artery of transplanted heart with unspecified angina pectoris |
| I25.790 | Atherosclerosis of other coronary artery bypass graft(s) with unstable angina pectoris |
| I25.791 | Atherosclerosis of other coronary artery bypass graft(s) with angina pectoris with documented spasm |
| I25.792 | Atherosclerosis of other coronary artery bypass graft(s) with refractory angina pectoris |
| I25.798 | Atherosclerosis of other coronary artery bypass graft(s) with other forms of angina pectoris |
| I25.799 | Atherosclerosis of other coronary artery bypass graft(s) with unspecified angina pectoris |
| I25.810 | Atherosclerosis of coronary artery bypass graft(s) without angina pectoris |
| I25.811 | Atherosclerosis of native coronary artery of transplanted heart without angina pectoris |
| I25.812 | Atherosclerosis of bypass graft of coronary artery of transplanted heart without angina pectoris |
| I25.82 | Chronic total occlusion of coronary artery |
| I25.83 | Coronary atherosclerosis due to lipid rich plaque |
| I25.84 | Coronary atherosclerosis due to calcified coronary lesion |
| I25.85 | Chronic coronary microvascular dysfunction |
| I25.89 | Other forms of chronic ischemic heart disease |
| I25.9 | Chronic ischemic heart disease, unspecified |
| T82.817A | Embolism due to cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.817D | Embolism due to cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.817S | Embolism due to cardiac prosthetic devices, implants and grafts, sequela |
| T82.827A | Fibrosis due to cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.827D | Fibrosis due to cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.827S | Fibrosis due to cardiac prosthetic devices, implants and grafts, sequela |
| T82.837A | Hemorrhage due to cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.837D | Hemorrhage due to cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.837S | Hemorrhage due to cardiac prosthetic devices, implants and grafts, sequela |
| T82.847A | Pain due to cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.847D | Pain due to cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.847S | Pain due to cardiac prosthetic devices, implants and grafts, sequela |
| T82.855A | Stenosis of coronary artery stent, initial encounter |
| T82.855D | Stenosis of coronary artery stent, subsequent encounter |
| T82.855S | Stenosis of coronary artery stent, sequela |
| T82.856A | Stenosis of peripheral vascular stent, initial encounter |
| T82.856D | Stenosis of peripheral vascular stent, subsequent encounter |
| T82.856S | Stenosis of peripheral vascular stent, sequela |
| T82.857A | Stenosis of other cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.857D | Stenosis of other cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.857S | Stenosis of other cardiac prosthetic devices, implants and grafts, sequela |
| T82.867A | Thrombosis due to cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.867D | Thrombosis due to cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.867S | Thrombosis due to cardiac prosthetic devices, implants and grafts, sequela |
| T82.897A | Other specified complication of cardiac prosthetic devices, implants and grafts, initial encounter |
| T82.897D | Other specified complication of cardiac prosthetic devices, implants and grafts, subsequent encounter |
| T82.897S | Other specified complication of cardiac prosthetic devices, implants and grafts, sequela |
| T82.9XXA | Unspecified complication of cardiac and vascular prosthetic device, implant and graft, initial encounter |
| T82.9XXD | Unspecified complication of cardiac and vascular prosthetic device, implant and graft, subsequent encounter |
| T82.9XXS | Unspecified complication of cardiac and vascular prosthetic device, implant and graft, sequela |
Frequently asked questions
Which ICD-10 codes support medical necessity for CPT C9603?
Medicare coverage policies (LCDs/NCDs and Billing & Coding articles) list 113 ICD-10 diagnosis codes that support medical necessity for CPT C9603. The covered codes are listed on this page. Coverage varies by MAC/state — always confirm against the policy that applies to you.
What is a medical-necessity (LCD/NCD) crosswalk?
A claim whose procedure isn't supported by a covered diagnosis denies as "not medically necessary" (CARC 50). CMS coverage policies define which diagnoses justify a procedure; this page is the ICD-10 → CPT C9603 view of that relationship.
More free billing tools: all crosswalks · NCCI edits · Medicare fees · denial codes
Informational only, not coding, billing, or legal advice. Based on CMS Medicare Coverage Database data; verify the current LCD/NCD for your MAC before billing.
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