ICD-10-CM Code First Notes · Chapter 9 · FY 2027 I00-I99
Code First Notes in Chapter 9: Diseases of the circulatory system ICD-10-CM
A Code First note means the underlying condition named in the note is sequenced before this code. In Chapter 9 (I00-I99), notes printed in the chapter name other codes 86 times, and Code First Notes anywhere in the Tabular List name the chapter’s codes 72 times, covering 57 distinct codes, categories and ranges. Switch views to read the list either way.
✓ From the official FY 2027 ICD-10-CM Tabular ListDefinitions follow the Official Guidelines, Section I.A
86
References in Its Notes
72
References to Its Codes
57
Chapter Codes Named
I00-I99
Chapter 9
Chapter 9
Code First Notes by the code that carries the note
30 of 30 shown
- I1A.0 Resistant hypertension
- I21.A1 Myocardial infarction type 2
- I21.A9 Other myocardial infarction type
- 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
- I26.03 Cement embolism of pulmonary artery with acute cor pulmonale
- complication of other artery following a procedure (T81.718)
- I26.04 Fat embolism of pulmonary artery with acute cor pulmonale
- I26.95 Cement embolism of pulmonary artery without acute cor pulmonale
- complication of other artery following a procedure (T81.718)
- I26.96 Fat embolism of pulmonary artery without acute cor pulmonale
- I31.31 Malignant pericardial effusion in diseases classified elsewhere
- I39 Endocarditis and heart valve disorders in diseases classified elsewhere
- Q fever (A78)
- I41 Myocarditis in diseases classified elsewhere
- pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4)
- I42.7 Cardiomyopathy due to drug and external agent
- I43 Cardiomyopathy in diseases classified elsewhere
- heart failure complicating abortion or ectopic or molar pregnancy (O00-O07, O08.8)
- heart failure due to hypertension (I11.0)
- heart failure due to hypertension with chronic kidney disease (I13.-)
- heart failure following surgery (I97.13-)
- obstetric surgery and procedures (O75.4)
- rheumatic heart failure (I09.81)
- I52 Other heart disorders in diseases classified elsewhere
- I5A Non-ischemic myocardial injury (non-traumatic)
- acute kidney failure (N17.-)
- acute myocarditis (I40.-)
- cardiomyopathy (I42.-)
- chronic kidney disease (CKD) (N18.-)
- heart failure (I50.-)
- hypertensive urgency (I16.0)
- nonrheumatic aortic valve disorders (I35.-)
- paroxysmal tachycardia (I47.-)
- pulmonary embolism (I26.-)
- pulmonary hypertension (I27.0, I27.2-)
- sepsis (A41.-)
- takotsubo syndrome (I51.81)
- I67.841 Reversible cerebrovascular vasoconstriction syndrome
- I68.0 Cerebral amyloid angiopathy
- underlying amyloidosis (E85.-)
- I70.92 Chronic total occlusion of artery of the extremities
- I76 Septic arterial embolism
- I79.8 Other disorders of arteries, arterioles and capillaries in diseases classified elsewhere
- amyloidosis (E85.-)
- I00 Rheumatic fever without heart involvement
- J17 Pneumonia in diseases classified elsewhere: rheumatic fever (I00)
- I09.81 Rheumatic heart failure
- I50 Heart failure: rheumatic heart failure (I09.81)
- I10 Essential (primary) hypertension
- I1A.0 Resistant hypertension: essential hypertension (I10)
- I11.0 Hypertensive heart disease with heart failure
- I50 Heart failure: heart failure due to hypertension (I11.0)
- N18 Chronic kidney disease (CKD): hypertensive chronic kidney disease (I12.-, I13.-)
- I1A.0 Resistant hypertension: secondary hypertension (I15.-)
- I16.0 Hypertensive urgency
- I5A Non-ischemic myocardial injury (non-traumatic): hypertensive urgency (I16.0)
- Z92.82 Status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility: acute myocardial infarction (I21.-, I22.-)
- Z92.82 Status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility: acute myocardial infarction (I21.-, I22.-)
- I25.82 Chronic total occlusion of coronary artery: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.83 Coronary atherosclerosis due to lipid rich plaque: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.84 Coronary atherosclerosis due to calcified coronary lesion: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.7- Atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris 35 codes
- I25.82 Chronic total occlusion of coronary artery: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.83 Coronary atherosclerosis due to lipid rich plaque: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.84 Coronary atherosclerosis due to calcified coronary lesion: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.82 Chronic total occlusion of coronary artery: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.83 Coronary atherosclerosis due to lipid rich plaque: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I25.84 Coronary atherosclerosis due to calcified coronary lesion: coronary atherosclerosis (I25.1-, I25.7-, I25.81-)
- I27.0 Primary pulmonary hypertension
- I5A Non-ischemic myocardial injury (non-traumatic): pulmonary hypertension (I27.0, I27.2-)
- I5A Non-ischemic myocardial injury (non-traumatic): pulmonary hypertension (I27.0, I27.2-)
- I33.0 Acute and subacute infective endocarditis
- I5A Non-ischemic myocardial injury (non-traumatic): nonrheumatic aortic valve disorders (I35.-)
- I5A Non-ischemic myocardial injury (non-traumatic): acute myocarditis (I40.-)
- I5A Non-ischemic myocardial injury (non-traumatic): cardiomyopathy (I42.-)
- I21.A1 Myocardial infarction type 2: paroxysmal tachycardia (I47.0-I47.9)
- I5A Non-ischemic myocardial injury (non-traumatic): paroxysmal tachycardia (I47.-)
- I5A Non-ischemic myocardial injury (non-traumatic): heart failure (I50.-)
- I51.81 Takotsubo syndrome
- I5A Non-ischemic myocardial injury (non-traumatic): takotsubo syndrome (I51.81)
- R29.7 National Institutes of Health Stroke Scale (NIHSS) score: the type of cerebral infarction (I60.-, I61.-, I62.-, I63.-)
- G46 Vascular syndromes of brain in cerebrovascular diseases: underlying cerebrovascular disease (I60-I69)
- R29.7 National Institutes of Health Stroke Scale (NIHSS) score: the type of cerebral infarction (I60.-, I61.-, I62.-, I63.-)
- R29.7 National Institutes of Health Stroke Scale (NIHSS) score: the type of cerebral infarction (I60.-, I61.-, I62.-, I63.-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- I70.33- Atherosclerosis of unspecified type of bypass graft(s) of the right leg with ulceration 7 codes
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.34- Atherosclerosis of unspecified type of bypass graft(s) of the left leg with ulceration 7 codes
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- I70.53- Atherosclerosis of nonautologous biological bypass graft(s) of the right leg with ulceration 7 codes
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.54- Atherosclerosis of nonautologous biological bypass graft(s) of the left leg with ulceration 7 codes
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: atherosclerosis of the lower extremities (I70.23-, I70.24-, I70.33-, I70.34-, I70.43-, I70.44-, I70.53-, I70.54-, I70.63-, I70.64-, I70.73-, I70.74-)
- I70.92 Chronic total occlusion of artery of the extremities: atherosclerosis of arteries of the extremities (I70.2-, I70.3-, I70.4-, I70.5-, I70.6-, I70.7-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: varicose ulcer (I83.0-, I83.2-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: varicose ulcer (I83.0-, I83.2-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: chronic venous hypertension (I87.31-, I87.33-)
- L97 Non-pressure chronic ulcer of lower limb, not elsewhere classified: chronic venous hypertension (I87.31-, I87.33-)
- I96 Gangrene, not elsewhere classified
- I50 Heart failure: heart failure following surgery (I97.13-)
- I97.190 Other postprocedural cardiac functional disturbances following cardiac surgery
- I21.A9 Other myocardial infarction type: , if applicable, postprocedural myocardial infarction following cardiac surgery (I97.190), or postprocedural myocardial infarction during cardiac surgery (I97.790)
- I97.790 Other intraoperative cardiac functional disturbances during cardiac surgery
- I21.A9 Other myocardial infarction type: , if applicable, postprocedural myocardial infarction following cardiac surgery (I97.190), or postprocedural myocardial infarction during cardiac surgery (I97.790)
The first view lists notes printed in this chapter (a note on a category or block applies to every code beneath it). The second lists codes of this chapter named by Code First Notes anywhere in the Tabular List, including notes in other chapters.
← Chapter 8: Diseases of the ear and mastoid processChapter 10: Diseases of the respiratory system →
Questions About Code First Notes
What does a Code First note mean?
A Code First note means the underlying condition named in the note is sequenced before the code that carries the note. Under the etiology/manifestation convention, a “code first” note appears at the manifestation code and a “use additional code” note at the etiology code (Section I.A.13). The FY 2027 Tabular List has 810 of them; 600 name other codes, with 736 references to 429 distinct codes, categories and ranges.
Can a code with a Code First note be the principal diagnosis?
Not when it is a manifestation code. Codes titled “in diseases classified elsewhere” are never permitted as the first-listed or principal diagnosis; they must follow the underlying condition. The etiology and manifestation page lists them all.
Related References
Source: FY 2027 ICD-10-CM Tabular List (CMS and NCHS) and the ICD-10-CM Official Guidelines for Coding and Reporting FY 2027, Section I.A. ICD List is not affiliated with CMS or NCHS.
