2026 ICD-10-CM Diagnosis Code J45.909Unspecified asthma, uncomplicated

ICD-10-CM Codes›J00–J99›J40-J4A›J45

ICD-10-CM J45.909
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J45.909 is a billable ICD-10-CM diagnosis code for unspecified asthma, uncomplicated. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 202 through 203. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Asthma.

This medical diagnosis code is frequently used in Pediatrics medical specialties to designate conditions such asthma.

Code Identity

ICD-10-CM Code
J45.909
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified asthma, uncomplicated
Short Description
Unspecified asthma, uncomplicated
Same as the full description in the CMS dataset.
Parent Code
J45.90
Unspecified asthma

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ40-J4AChronic lower respiratory diseases
CategoryJ45Asthma
This CodeJ45.909Unspecified asthma, uncomplicated

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Absent from work or school due to asthma
  • Airways obstruction irreversible
  • Allergic asthma
  • Allergic asthma caused by Dermatophagoides farinae
  • Allergic asthma caused by Dermatophagoides pteronyssinus
  • Allergic asthma without status asthmaticus
  • Allergic bronchitis
  • Asthma
  • Asthma - currently active
  • Asthma - currently dormant
  • Asthma causes daytime symptoms 1 to 2 times per month
  • Asthma causes daytime symptoms 1 to 2 times per week
  • Asthma causes daytime symptoms most days
  • Asthma causes night symptoms 1 to 2 times per month
  • Asthma causing night waking
  • Asthma confirmed
  • Asthma daytime symptoms
  • Asthma disturbing sleep
  • Asthma disturbs sleep frequently
  • Asthma disturbs sleep weekly
  • Asthma in mother complicating childbirth
  • Asthma in pregnancy
  • Asthma limiting activities
  • Asthma limits walking on the flat
  • Asthma limits walking up hills or stairs
  • Asthma monitor offer default
  • Asthma monitoring check done
  • Asthma monitoring due
  • Asthma monitoring status
  • Asthma never causes daytime symptoms
  • Asthma never causes night symptoms
  • Asthma never disturbs sleep
  • Asthma never restricts exercise
  • Asthma night-time symptoms
  • Asthma not disturbing sleep
  • Asthma not limiting activities
  • Asthma restricts exercise
  • Asthma severely restricts exercise
  • Asthma sometimes restricts exercise
  • Asthma treatment compliance satisfactory
  • Asthma treatment compliance unsatisfactory
  • Asthma with irreversible airway obstruction
  • Asthma without status asthmaticus
  • Asthmatic bronchitis
  • Chemical-induced asthma
  • Childhood asthma
  • Chronic allergic bronchitis
  • Disorder confirmed
  • Finding of respiratory obstruction
  • Hay fever with asthma
  • IgE-mediated allergic asthma
  • Inhaled steroid-dependent asthma
  • Intrinsic asthma
  • Intrinsic asthma without status asthmaticus
  • Late onset asthma
  • Mild asthma
  • Mixed asthma
  • Non-IgE mediated allergic asthma
  • Occupational asthma
  • Oral steroid-dependent asthma
  • Persistent asthma
  • Persistent asthma, well controlled
  • Reactive airway disease
  • Seasonal allergic rhinitis
  • Seasonal asthma
  • Steroid dependent asthma
  • Uncomplicated allergic asthma
  • Uncomplicated asthma
  • Uncomplicated non-allergic asthma
  • Uncontrolled asthma

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Asthma NOS

Type 2 Excludes

  • lung diseases due to external agents J60 J70

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • allergic extrinsic
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • childhood
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • late-onset
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • mixed
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • nonallergic (intrinsic)
    • Asthma, asthmatic(bronchial) (catarrh) (spasmodic)
      • predominantly allergic
    • Bronchitis(diffuse) (fibrinous) (hypostatic) (infective) (membranous)
      • allergic (acute)
    • Dyspnea(nocturnal) (paroxysmal)
      • asthmatic (bronchial)
    • Dyspnea(nocturnal) (paroxysmal)
      • asthmatic (bronchial)
        • with
          • bronchitis
    • Fever(inanition) (of unknown origin) (persistent) (with chills) (with rigor)
      • hay (allergic)
        • with asthma (bronchial)
    • IgE asthma
    • Obstruction, obstructed, obstructive
      • airway
        • with
          • asthma
    • Rhinitis(atrophic) (catarrhal) (chronic) (croupous) (fibrinous) (granulomatous) (hyperplastic) (hypertrophic) (membranous) (obstructive) (purulent) (suppurative) (ulcerative)
      • allergic
        • with asthma

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR RSP009
Asthma
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Airway Remodeling

    the structural changes in the number, mass, size and/or composition of the airway tissues.

  • Asthma

    a form of bronchial disorder with three distinct components: airway hyper-responsiveness (respiratory hypersensitivity), airway inflammation, and intermittent airway obstruction. it is characterized by spasmodic contraction of airway smooth muscle, wheezing, and dyspnea (dyspnea, paroxysmal).

  • Asthma, Aspirin-Induced

    asthmatic adverse reaction (e.g., bronchoconstriction) to conventional nsaids including aspirin use.

  • Asthma, Exercise-Induced

    asthma attacks following a period of exercise. usually the induced attack is short-lived and regresses spontaneously. the magnitude of postexertional airway obstruction is strongly influenced by the environment in which exercise is performed (i.e. inhalation of cold air during physical exertion markedly augments the severity of the airway obstruction; conversely, warm humid air blunts or abolishes it).

  • Asthma, Occupational

    asthma attacks caused, triggered, or exacerbated by occupational exposure.

  • Asthma-Chronic Obstructive Pulmonary Disease Overlap Syndrome

    syndrome with clinical features of both asthma and copd.

  • Conyza

    a plant genus of the family asteraceae. members contain alkenynes, daucosterol, friedelinol, conyzasaponins and other triterpenes.

  • Cough-Variant Asthma

    asthma which is characterized by chronic cough that is nonproductive without other asthmatic symptoms, e.g., wheezing, and paroxysmal dyspnea. cough-variant asthma is accompanied by airway hypersensitivity and may progress to classical asthma without treatment.

  • Dyspnea, Paroxysmal

    a disorder characterized by sudden attacks of respiratory distress in at rest patients with heart failure and pulmonary edema. it usually occurs at night after several hours of sleep in a reclining position. patients awaken with a feeling of suffocation, coughing, a cold sweat, and tachycardia. when there is significant wheezing, it is called cardiac asthma.

  • Status Asthmaticus

    a sudden intense and continuous aggravation of a state of asthma, marked by dyspnea to the point of exhaustion and collapse and not responding to the usual therapeutic efforts.

  • Tylophora

    a plant genus of the family asclepiadaceae. members contain phenanthro-indolizidine alkaloids.

  • Occupational Exposure

    the exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.

Patient EducationClinical

Asthma

Asthma is a chronic (long-term) lung disease. It affects your airways, the tubes that carry air in and out of your lungs. When you have asthma, your airways can become inflamed and narrowed. This can cause wheezing, coughing, and tightness in your chest. When these symptoms get worse than usual, it is called an asthma attack or flare-up.

The full article covers:

  • What is asthma?
  • What causes asthma?
  • Who is at risk for asthma?
  • What are the symptoms of asthma?
  • How is asthma diagnosed?
  • What are the treatments for asthma?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert J45.909 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
493.90 Asthma NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About J45.909Overview

Is J45.909 (Unspecified asthma) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified asthma, uncomplicated on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does J45.909 group to?

When unspecified asthma, uncomplicated is the principal diagnosis on an inpatient stay, it groups to MS-DRG 202, 203, with relative weights from 0.6700 to 0.9712 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of J45.909?

Under the General Equivalence Mappings, unspecified asthma, uncomplicated converts to ICD-9-CM 493.90 (asthma NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.