J45 – Asthma

ICD-10-CM 2027 diagnosis code · Chronic lower respiratory diseases

Non-billable header

ICD-10-CM code J45

Code: J45 (claims format: J45)
Description: Asthma
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 10. Diseases of the respiratory system (J00-J99)
Block: J40-J4B Chronic lower respiratory diseases

Billable codes under J45

J45 is a header code and cannot be used on claims. Choose the most specific code:

J45.2 – Mild intermittent asthmaHeader (more codes below)
J45.3 – Mild persistent asthmaHeader (more codes below)
J45.4 – Moderate persistent asthmaHeader (more codes below)
J45.5 – Severe persistent asthmaHeader (more codes below)
J45.9 – Other and unspecified asthmaHeader (more codes below)

Notes for J45

Includes:

allergic (predominantly) asthma
allergic bronchitis NOS
allergic rhinitis with asthma
atopic asthma
extrinsic allergic asthma
hay fever with asthma
idiosyncratic asthma
intrinsic nonallergic asthma
nonallergic asthma

Excludes1 (not coded here):

detergent asthma (J69.8)
miner's asthma (J60)
wheezing NOS (R06.2)
wood asthma (J67.8)

Excludes2 (not included here):

asthma with chronic obstructive pulmonary disease (J44.89)
chronic asthmatic (obstructive) bronchitis (J44.89)
chronic obstructive asthma (J44.89)
other specified chronic obstructive pulmonary disease (J44.89)

Use additional code:

code to identify:
eosinophilic asthma (J82.83)
exposure to environmental tobacco smoke (Z77.22)
exposure to tobacco smoke in the perinatal period (P96.81)
history of tobacco dependence (Z87.891)
occupational exposure to environmental tobacco smoke (Z57.31)
tobacco dependence (F17.-)
tobacco use (Z72.0)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block J40-J4B

Excludes1 (not coded here):

bronchitis due to chemicals, gases, fumes and vapors (J68.0)

Excludes2 (not included here):

cystic fibrosis (E84.-)

Frequently asked questions

What is ICD-10 code J45?

J45 is the ICD-10-CM code for asthma, in the block J40-J4B (Chronic lower respiratory diseases).

Is J45 a billable code?

No. J45 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.