2019 ICD-10-CM Diagnosis Code I20.0

Unstable angina

    2016 2017 2018 2019 Billable/Specific Code
  • I20.0 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
  • The 2019 edition of ICD-10-CM I20.0 became effective on October 1, 2018.
  • This is the American ICD-10-CM version of I20.0 - other international versions of ICD-10 I20.0 may differ.
Applicable To
  • Accelerated angina
  • Crescendo angina
  • De novo effort angina
  • Intermediate coronary syndrome
  • Preinfarction syndrome
  • Worsening effort angina
The following code(s) above I20.0 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to I20.0:
  • I00-I99
    2019 ICD-10-CM Range I00-I99

    Diseases of the circulatory system

    Type 2 Excludes
    • certain conditions originating in the perinatal period (P04-P96)
    • certain infectious and parasitic diseases (A00-B99)
    • complications of pregnancy, childbirth and the puerperium (O00-O9A)
    • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
    • endocrine, nutritional and metabolic diseases (E00-E88)
    • injury, poisoning and certain other consequences of external causes (S00-T88)
    • neoplasms (C00-D49)
    • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
    • systemic connective tissue disorders (M30-M36)
    • transient cerebral ischemic attacks and related syndromes (G45.-)
    Diseases of the circulatory system
  • I20-I25
    2019 ICD-10-CM Range I20-I25

    Ischemic heart diseases

    Use Additional
    • code to identify presence of hypertension (I10-I16)
    Ischemic heart diseases
  • I20
    ICD-10-CM Diagnosis Code I20

    Angina pectoris

      2016 2017 2018 2019 Non-Billable/Non-Specific Code
    Type 1 Excludes
    • angina pectoris with atherosclerotic heart disease of native coronary arteries (I25.1-)
    • atherosclerosis of coronary artery bypass graft(s) and coronary artery of transplanted heart with angina pectoris (I25.7-)
    • postinfarction angina (I23.7)
    Use Additional
    • code to identify:
    • exposure to environmental tobacco smoke (Z77.22)
    • history of tobacco dependence (Z87.891)
    • occupational exposure to environmental tobacco smoke (Z57.31)
    • tobacco dependence (F17.-)
    • tobacco use (Z72.0)
    Angina pectoris
Approximate Synonyms
  • Preinfarction syndrome
Clinical Information
  • Angina pectoris (or equivalent type of ischemic discomfort) which has recently changed in frequency, duration, intensity, or occurs at rest.
  • Angina pectoris (or equivalent type of ischemic discomfort) with any 1 of the 3 following features: a) angina occurring at rest and prolonged, usually greater than 20 minutes; b) new onset angina of at least canadian cardiovascular society grading scale (or ccs classification system) classification severity iii or greater; c) recent acceleration in angina accentuated by an increase in severity of at least 1 ccs class to at least ccs class iii. The biomarkers of necrosis are below the threshold of myocardial infarction.
  • Angina pectoris (or equivalent type of ischemic discomfort) with any 1 of the 3 following features: a) angina occurring at rest and prolonged, usually greater than 20 minutes; b) new onset angina of at least canadian cardiovascular society grading scale (or ccs classification system) classification severity iii or greater; c) recent acceleration in angina accentuated by an increase in severity of at least 1 ccs class to at least ccs class iii. The biomarkers of necrosis are below the threshold of myocardial infarction. (nih roadmap cardiovascular data standards working group)
  • Precordial pain at rest, which may precede a myocardial infarction.
ICD-10-CM I20.0 is grouped within Diagnostic Related Group(s) (MS-DRG v36.0):
  • 311 Angina pectoris

Convert I20.0 to ICD-9-CM

Code History
  • 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
  • 2017 (effective 10/1/2016): No change
  • 2018 (effective 10/1/2017): No change
  • 2019 (effective 10/1/2018): No change
Code annotations containing back-references to I20.0:
  • Type 1 Excludes: I25.710
    , I25.720
    , I25.730
    , I25.790
    , I25.700
    , I25.110
    ICD-10-CM Diagnosis Code I25.710

    Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina without atherosclerosis of autologous vein coronary artery bypass graft(s) (I20.0)
    Type 2 Excludes
    • embolism or thrombus of coronary artery bypass graft(s) (T82.8-)
    ICD-10-CM Diagnosis Code I25.720

    Atherosclerosis of autologous artery coronary artery bypass graft(s) with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina without atherosclerosis of autologous artery coronary artery bypass graft(s) (I20.0)
    ICD-10-CM Diagnosis Code I25.730

    Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina without atherosclerosis of nonautologous biological coronary artery bypass graft(s) (I20.0)
    ICD-10-CM Diagnosis Code I25.790

    Atherosclerosis of other coronary artery bypass graft(s) with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina without atherosclerosis of other coronary artery bypass graft(s) (I20.0)
    ICD-10-CM Diagnosis Code I25.700

    Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina pectoris without atherosclerosis of coronary artery bypass graft (I20.0)
    ICD-10-CM Diagnosis Code I25.110

    Atherosclerotic heart disease of native coronary artery with unstable angina pectoris

      2016 2017 2018 2019 Billable/Specific Code Adult Dx (15-124 years)
    Type 1 Excludes
    • unstable angina without atherosclerotic heart disease (I20.0)

Diagnosis Index entries containing back-references to I20.0:
  • Angina (attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor) I20.9
    ICD-10-CM Diagnosis Code I20.9

    Angina pectoris, unspecified

      2016 2017 2018 2019 Billable/Specific Code
    Applicable To
    • Angina NOS
    • Anginal syndrome
    • Cardiac angina
    • Ischemic chest pain
    • unstable I20.0
  • Impending
    • coronary syndrome I20.0
    • myocardial infarction I20.0
  • Infarct, infarction
    • impending I20.0 (myocardium)
  • Syndrome - see also Disease
    • coronary
      • insufficiency or intermediate I20.0
    • impending coronary I20.0
    • intermediate coronary I20.0 (artery)
    • preinfarction I20.0

ICD-10-CM Codes Adjacent To I20.0
I15.0 Renovascular hypertension
I15.1 Hypertension secondary to other renal disorders
I15.2 Hypertension secondary to endocrine disorders
I15.8 Other secondary hypertension
I15.9 Secondary hypertension, unspecified
I16 Hypertensive crisis
I16.0 Hypertensive urgency
I16.1 Hypertensive emergency
I16.9 Hypertensive crisis, unspecified
I20 Angina pectoris
I20.0 Unstable angina
I20.1 Angina pectoris with documented spasm
I20.8 Other forms of angina pectoris
I20.9 Angina pectoris, unspecified
I21 Acute myocardial infarction
I21.0 ST elevation (STEMI) myocardial infarction of anterior wall
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
I21.1 ST elevation (STEMI) myocardial infarction of inferior wall
I21.11 ST elevation (STEMI) myocardial infarction involving right coronary artery

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.