ICD-10 code guides
Reviewed July 1, 2026

ICD-10 codes for asthma

ICD-10-CM asthma codes encode severity (intermittent vs mild/moderate/severe persistent) and acuity (uncomplicated, with exacerbation, with status asthmaticus). J45.909 is the fallback, not the default.

J45.909 billable

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Paste a note or record audio. Notat’s FactsContext™ engine extracts the raw clinical facts first, then suggests codes from that context so you can inspect the evidence before using anything.

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How to use this tool

1

Paste or dictate a de-identified clinical note — a few sentences is enough.

2

Press Get codes. The coding system is fixed on this page.

3

Review each suggested code and its evidence, then copy the codes you agree with.

Clinical note

ICD-10-CM

Extracted codes

Evidence stays attached for review.

Paste a clinical note or load an example, then press Get codes. Suggestions appear here with the supporting evidence.

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Asthma ICD-10 codes

Start with the primary code, then move to a more specific related code when the documentation supports it.

CodeDescriptionSystem

J45.909

Unspecified asthma, uncomplicated

ICD-10-CM

J45.20

Mild intermittent asthma, uncomplicated

ICD-10-CM

J45.40

Moderate persistent asthma, uncomplicated

ICD-10-CM

J45.50

Severe persistent asthma, uncomplicated

ICD-10-CM

J45.901

Unspecified asthma with (acute) exacerbation

ICD-10-CM

J45.902

Unspecified asthma with status asthmaticus

ICD-10-CM

How to choose the right code

Document severity classification at least annually and code it: intermittent (J45.2-), mild persistent (J45.3-), moderate persistent (J45.4-), severe persistent (J45.5-). During an attack, the sixth character changes: -1 for exacerbation, -2 for status asthmaticus. Severity plus acuity together (e.g. J45.41, moderate persistent with exacerbation) is the fully specific code.

Documentation example

Asthma review. Using salbutamol 4–5 times weekly, waking with cough twice weekly — consistent with moderate persistent asthma. Today wheezing with peak flow 65% of best after URTI. Prednisolone burst started; stepped up to medium-dose ICS/LABA.

Suggested:

J45.41

Not direct transcript guessing

FactsContext extracts clinical facts first: diagnoses, symptoms, negatives, findings, test results, medications, and plan decisions.

Raw facts stay usable

The clinician can read and reuse the extracted medical context directly, independent of the generated note.

Built for review

AI suggestions are not a substitute for clinician judgment, payer rules, local coding policy, or the official code set.

FAQ

When should I avoid J45.909?

Whenever severity is documented or documentable. Reliever frequency and night symptoms in the note support a persistent-severity code, which reflects the patient’s actual disease burden.

What is the difference between exacerbation and status asthmaticus?

An exacerbation is an acute worsening responding to treatment; status asthmaticus is a severe attack not responding to standard bronchodilator therapy — an emergency, coded with the -2 sixth character.

Can AI map my asthma note to the specific code?

Yes. Notat extracts reliever use, night waking, and acute findings as clinical facts and proposes the severity- and acuity-specific J45 code with its evidence.

Related ICD-10 guides

Keep moving through the condition hub, or open the general medical coding guide for more coding systems and extractors.

Medical coding hub