J45.901
Unspecified asthma with (acute) exacerbation
Billable FY2026 2025-10-01 → 2026-09-30
This is the unspecified option. 2 more
specific codes sit alongside it. Worth
checking whether the documentation supports one of them.
Exclusions 19 never code together
J45code
Excludes1
J40-J4Ablock
J00-J99chapter
Excludes2
- certain conditions originating in the perinatal period (P04-P96)P04-P96
- certain infectious and parasitic diseases (A00-B99)A00-B99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)O00-O9A
- congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Q00-Q99
- endocrine, nutritional and metabolic diseases (E00-E88)E00-E88
- injury, poisoning and certain other consequences of external causes (S00-T88)S00-T88
- neoplasms (C00-D49)C00-D49
- smoke inhalation (T59.81-)T59.81-
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)R00-R94
Excludes1 — never code together. The excluded condition and this one are mutually exclusive.
Excludes2 — not included here, but the patient may have both. Code both when documented.
Instructional notes 25
J45code
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
Use additional code
- code to identify:
- eosinophilic asthma (J82.83)J82.83
- exposure to environmental tobacco smoke (Z77.22)Z77.22
- exposure to tobacco smoke in the perinatal period (P96.81)P96.81
- history of tobacco dependence (Z87.891)Z87.891
- occupational exposure to environmental tobacco smoke (Z57.31)Z57.31
- tobacco dependence (F17.-)F17.-
- tobacco use (Z72.0)Z72.0
J00-J99chapter
Notes
- When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).J40
Use additional code
- code, where applicable, to identify:
- exposure to environmental tobacco smoke (Z77.22)Z77.22
- exposure to tobacco smoke in the perinatal period (P96.81)P96.81
- history of tobacco dependence (Z87.891)Z87.891
- occupational exposure to environmental tobacco smoke (Z57.31)Z57.31
- tobacco dependence (F17.-)F17.-
- tobacco use (Z72.0)Z72.0
Index entries leading here 6
- Obstruction, obstructed, obstructive
- Rhinitis (atrophic) (catarrhal) (chronic) (croupous) (fibrinous) (granulomatous) (hyperplastic) (hypertrophic) (membranous) (obstructive) (purulent) (suppurative) (ulcerative) J31.0
- Bronchitis (diffuse) (fibrinous) (hypostatic) (infective) (membranous) J40
- Asthma, asthmatic (bronchial) (catarrh) (spasmodic) J45.909
- allergic extrinsic J45.909
- with
- exacerbation (acute) J45.901
- with
- mixed J45.909
- with
- exacerbation (acute) J45.901
- with
- nonallergic (intrinsic) J45.909
- with
- exacerbation (acute) J45.901
- with
- with
- exacerbation (acute) J45.901
- late-onset J45.909
- with
- exacerbation (acute) J45.901
- with
- childhood J45.909
- with
- exacerbation (acute) J45.901
- with
- allergic extrinsic J45.909
- Dyspnea (nocturnal) (paroxysmal) R06.00
- Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) R50.9
Alongside this code 2 same parent — J45.90
Additional references
AHA Coding Clinic® Licence required
Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.