I21.A1UpcomingBillable / specific

Myocardial infarction type 2

Code-level instructions

Code first

, if applicable, the underlying cause, such as:
anemia (D50.0-D64.9)
chronic obstructive pulmonary disease (J44.-)
paroxysmal tachycardia (I47.0-I47.9)
shock (R57.0-R57.9)

I21 · Inherited instructions

Use additional code

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)

I20-I25 · Inherited instructions

Code also

the presence of hypertension (I10-I1A)

Excludes 2 · 13

I21 · Acute myocardial infarction

Excludes 2

old myocardial infarction (I25.2)
postmyocardial infarction syndrome (I24.1)
subsequent type 1 myocardial infarction (I22.-)

Chapters 9 · Diseases of the circulatory system (I00-I99)

Excludes 2

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.-)

Claims & coverage

Coverage depends on the payer, service and applicable policy. A billable code does not guarantee payment.

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Use the service date for outpatient/professional claims and the discharge date for hospital inpatient claims. Earlier encounters use ICD-9-CM; each individual code must also be valid for the applicable date.

Official coding guidelines → · CMS ↗

Check Medicare coverage ↗

First observed · 2017-10-01

Code history

Latest recorded change · FY2025

ChangedUnchanged

FY2025

Effective from 2024-10-01

Code-level rules changed

Myocardial infarction type 2

Billable diagnosis code

CDC/NCHS · FY2025

All editions (17)

All editions	Effective from	Code history
FY2018	2017-10-01	Added
FY2019	2018-10-01	No tabular change
FY2020	2019-10-01	Code-level rules changed
FY2020 · April	2020-04-01	No tabular change
FY2021	2020-10-01	No tabular change
FY2021 · 01-01	2021-01-01	No tabular change
FY2022	2021-10-01	Inherited rules changed
FY2022 · 04-01	2022-04-01	No tabular change
FY2023	2022-10-01	No tabular change
FY2023 · 04-01	2023-04-01	No tabular change
FY2024	2023-10-01	Inherited rules changed
FY2024 · 04-01	2024-04-01	No tabular change
FY2025	2024-10-01	Code-level rules changed
FY2025 · 04-01	2025-04-01	No tabular change
FY2026	2025-10-01	No tabular change
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Historical ICD-9 mappings · 2018

Historical mapping only; not an automatic code substitution.

410.90 · Approximate
410.91 · Approximate
410.92 · Approximate

CDC/NCHS · GEM 2018

Code-level instructions

Inclusion terms

Myocardial infarction due to demand ischemia
Myocardial infarction secondary to ischemic imbalance

Code first

, if applicable, the underlying cause, such as:
anemia (D50.0-D64.9)
chronic obstructive pulmonary disease (J44.-)
paroxysmal tachycardia (I47.0-I47.9)
shock (R57.0-R57.9)

Inherited instructions

I21 · Acute myocardial infarction

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

Excludes 2

old myocardial infarction (I25.2)
postmyocardial infarction syndrome (I24.1)
subsequent type 1 myocardial infarction (I22.-)

Use additional code

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)

Chapters 9 · Diseases of the circulatory system (I00-I99)

Excludes 2

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.-)

I20-I25 · Ischemic heart diseases (I20-I25)

Code also

the presence of hypertension (I10-I1A)

Official index references (8)

Infarct, infarction (6)

Ischemia, ischemic (2)

Ischemia, ischemic › demand(coronary) › with myocardial infarctionDisease index
Ischemia, ischemic › demand(coronary) › resulting in myocardial infarctionDisease index

Official conversion history

Historical assignments from the CDC conversion table support data retrieval. They do not authorize substituting a previous code for the current code.

Release dates 2017-10-01

Previous assignment: I21.3

Related codes

Other entries in the same category; these are not automatic substitutes.

Code	Description	Category · further specificity required
I21.A9	Other myocardial infarction type	Billable / specific

Official titles and instructions are preserved in their source language. Official sources ↗

References from other codes (2)

I22 · Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction

Excludes 1 · subsequent myocardial infarction, type 2 (I21.A1)

I24.8 · Other forms of acute ischemic heart disease

Excludes 1 · myocardial infarction due to demand ischemia (I21.A1)

I21.A1UpcomingBillable / specific

Myocardial infarction type 2

Code-level instructions

Code first

, if applicable, the underlying cause, such as:
anemia (D50.0-D64.9)
chronic obstructive pulmonary disease (J44.-)
paroxysmal tachycardia (I47.0-I47.9)
shock (R57.0-R57.9)

I21 · Inherited instructions

Use additional code

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)

I20-I25 · Inherited instructions

Code also

the presence of hypertension (I10-I1A)

Excludes 2 · 13

I21 · Acute myocardial infarction

Excludes 2

old myocardial infarction (I25.2)
postmyocardial infarction syndrome (I24.1)
subsequent type 1 myocardial infarction (I22.-)

Chapters 9 · Diseases of the circulatory system (I00-I99)

Excludes 2

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.-)

Claims & coverage

Coverage depends on the payer, service and applicable policy. A billable code does not guarantee payment.

When ICD-10-CM is required

For US diagnosis claims covered by HIPAA, ICD-10-CM is required from October 1, 2015.

Official coding guidelines → · CMS ↗

Check Medicare coverage ↗

First observed · 2017-10-01

Code history

Latest recorded change · FY2025

ChangedUnchanged

FY2025

Effective from 2024-10-01

Code-level rules changed

Myocardial infarction type 2

Billable diagnosis code

CDC/NCHS · FY2025

All editions (17)

All editions	Effective from	Code history
FY2018	2017-10-01	Added
FY2019	2018-10-01	No tabular change
FY2020	2019-10-01	Code-level rules changed
FY2020 · April	2020-04-01	No tabular change
FY2021	2020-10-01	No tabular change
FY2021 · 01-01	2021-01-01	No tabular change
FY2022	2021-10-01	Inherited rules changed
FY2022 · 04-01	2022-04-01	No tabular change
FY2023	2022-10-01	No tabular change
FY2023 · 04-01	2023-04-01	No tabular change
FY2024	2023-10-01	Inherited rules changed
FY2024 · 04-01	2024-04-01	No tabular change
FY2025	2024-10-01	Code-level rules changed
FY2025 · 04-01	2025-04-01	No tabular change
FY2026	2025-10-01	No tabular change
FY2026 · April	2026-04-01	No tabular change
FY2027	2026-10-01	No tabular change

Historical ICD-9 mappings · 2018

Historical mapping only; not an automatic code substitution.

410.90 · Approximate
410.91 · Approximate
410.92 · Approximate

CDC/NCHS · GEM 2018

Code-level instructions

Inclusion terms

Myocardial infarction due to demand ischemia
Myocardial infarction secondary to ischemic imbalance

Code first

, if applicable, the underlying cause, such as:
anemia (D50.0-D64.9)
chronic obstructive pulmonary disease (J44.-)
paroxysmal tachycardia (I47.0-I47.9)
shock (R57.0-R57.9)

Inherited instructions

I21 · Acute myocardial infarction

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

Excludes 2

old myocardial infarction (I25.2)
postmyocardial infarction syndrome (I24.1)
subsequent type 1 myocardial infarction (I22.-)

Use additional code

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)

Chapters 9 · Diseases of the circulatory system (I00-I99)

Excludes 2

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.-)

I20-I25 · Ischemic heart diseases (I20-I25)

Code also

the presence of hypertension (I10-I1A)

Official index references (8)

Infarct, infarction (6)

Ischemia, ischemic (2)

Ischemia, ischemic › demand(coronary) › with myocardial infarctionDisease index
Ischemia, ischemic › demand(coronary) › resulting in myocardial infarctionDisease index

Official conversion history

Historical assignments from the CDC conversion table support data retrieval. They do not authorize substituting a previous code for the current code.

Release dates 2017-10-01

Previous assignment: I21.3

Related codes

Other entries in the same category; these are not automatic substitutes.

Code	Description	Category · further specificity required
I21.A9	Other myocardial infarction type	Billable / specific

Official titles and instructions are preserved in their source language. Official sources ↗

References from other codes (2)

I22 · Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction

Excludes 1 · subsequent myocardial infarction, type 2 (I21.A1)

I24.8 · Other forms of acute ischemic heart disease

Excludes 1 · myocardial infarction due to demand ischemia (I21.A1)