2017/18 ICD-10-CM Diagnosis Code I21.A1

Myocardial infarction type 2

Applicable To
  • Myocardial infarction due to demand ischemia
  • Myocardial infarction secondary to ischemic imbalance
Code Also
Code Also Help
A code also note instructs that 2 codes may be required to fully describe a condition but the sequencing of the two codes is discretionary, depending on the severity of the conditions and the reason for the encounter.
  • the underlying cause, if known and applicable, such as:
  • anemia (
    ICD-10-CM Diagnosis Code D50.0

    Iron deficiency anemia secondary to blood loss (chronic)

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Posthemorrhagic anemia (chronic)
    Type 1 Excludes
    • acute posthemorrhagic anemia (D62)
    • congenital anemia from fetal blood loss (P61.3)
    D50.0-
    ICD-10-CM Diagnosis Code D64.9

    Anemia, unspecified

      2016 2017 2018 Billable/Specific Code
    D64.9
    )
  • chronic obstructive pulmonary disease (
    ICD-10-CM Diagnosis Code J44
    • J44 Other chronic obstructive pulmonary disease
      • J44.0 Chronic obstructive pulmonary disease with ac...
      • J44.1 Chronic obstructive pulmonary disease with (a...
      • J44.9 Chronic obstructive pulmonary disease, unspec...
    J44.-
    )
  • heart failure (
    ICD-10-CM Diagnosis Code I50
    • I50 Heart failure
      • I50.1 Left ventricular failure, unspecified
      • I50.2 Systolic (congestive) heart failure
        • I50.20 Unspecified systolic (congestive) heart failu...
        • I50.21 Acute systolic (congestive) heart failure
        • I50.22 Chronic systolic (congestive) heart failure
        • I50.23 Acute on chronic systolic (congestive) heart ...
      • I50.3 Diastolic (congestive) heart failure
        • I50.30 Unspecified diastolic (congestive) heart fail...
        • I50.31 Acute diastolic (congestive) heart failure
        • I50.32 Chronic diastolic (congestive) heart failure
        • I50.33 Acute on chronic diastolic (congestive) heart...
      • I50.4 Combined systolic (congestive) and diastolic ...
        • I50.40 Unspecified combined systolic (congestive) an...
        • I50.41 Acute combined systolic (congestive) and dias...
        • I50.42 Chronic combined systolic (congestive) and di...
        • I50.43 Acute on chronic combined systolic (congestiv...
      • I50.8 Other heart failure
        • I50.81 Right heart failure
          • I50.810 …… unspecified
          • I50.811 Acute right heart failure
          • I50.812 Chronic right heart failure
          • I50.813 Acute on chronic right heart failure
          • I50.814 Right heart failure due to left heart failure...
        • I50.82 Biventricular heart failure
        • I50.83 High output heart failure
        • I50.84 End stage heart failure
        • I50.89 Other heart failure
      • I50.9 Heart failure, unspecified
    I50.-
    )
  • paroxysmal tachycardia (
    ICD-10-CM Diagnosis Code I47.0

    Re-entry ventricular arrhythmia

      2016 2017 2018 Billable/Specific Code
    I47.0-
    ICD-10-CM Diagnosis Code I47.9

    Paroxysmal tachycardia, unspecified

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Bouveret (-Hoffman) syndrome
    I47.9
    )
  • renal failure (
    ICD-10-CM Diagnosis Code N17.0

    Acute kidney failure with tubular necrosis

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Acute tubular necrosis
    • Renal tubular necrosis
    • Tubular necrosis NOS
    N17.0-
    ICD-10-CM Diagnosis Code N19

    Unspecified kidney failure

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Uremia NOS
    Type 1 Excludes
    • acute kidney failure (N17.-)
    • chronic kidney disease (N18.-)
    • chronic uremia (N18.9)
    • extrarenal uremia (R39.2)
    • prerenal uremia (R39.2)
    • renal insufficiency (acute) (N28.9)
    • uremia of newborn (P96.0)
    N19
    )
  • shock (
    ICD-10-CM Diagnosis Code R57.0

    Cardiogenic shock

      2016 2017 2018 Billable/Specific Code
    Type 2 Excludes
    R57.0-
    ICD-10-CM Diagnosis Code R57.9

    Shock, unspecified

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Failure of peripheral circulation NOS
    R57.9
    )
The following code(s) above I21.A1 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 I21.A1:
  • I00-I99
    2018 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
    2018 ICD-10-CM Range I20-I25

    Ischemic heart diseases

    Use Additional
    • code to identify presence of hypertension (I10-I16)
    Ischemic heart diseases
  • I21
    ICD-10-CM Diagnosis Code I21

    Acute myocardial infarction

      2016 2017 2018 - Revised Code Non-Billable/Non-Specific Code
    Includes
    • cardiac infarction
    • coronary (artery) embolism
    • coronary (artery) occlusion
    • coronary (artery) rupture
    • coronary (artery) thrombosis
    • infarction of heart, myocardium, or ventricle
    • myocardial infarction specified as acute or with a stated duration of 4 weeks (28 days) or less from onset
    Type 2 Excludes
    • old myocardial infarction (I25.2)
    • postmyocardial infarction syndrome (I24.1)
    • subsequent type 1 myocardial infarction (I22.-)
    Use Additional
    • code, if applicable, to identify:
    • exposure to environmental tobacco smoke (Z77.22)
    • history of tobacco dependence (Z87.891)
    • occupational exposure to environmental tobacco smoke (Z57.31)
    • status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82)
    • tobacco dependence (F17.-)
    • tobacco use (Z72.0)
    Acute myocardial infarction
ICD-10-CM I21.A1 is grouped within Diagnostic Related Group(s) (MS-DRG v35.0):

Convert I21.A1 to ICD-9-CM

Code History
Code annotations containing back-references to I21.A1:

Diagnosis Index entries containing back-references to I21.A1:

ICD-10-CM Codes Adjacent To I21.A1
I21.1 ST elevation (STEMI) myocardial infarction of inferior 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
I21.2 ST elevation (STEMI) myocardial infarction of other sites
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.A Other type of myocardial infarction
I21.A1 Myocardial infarction type 2
I21.A9 Other myocardial infarction type
I22 Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction
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
I23 Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)
I23.0 Hemopericardium as current complication following acute myocardial infarction
I23.1 Atrial septal defect as current complication following acute myocardial infarction

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