J45.42 — Moderate persistent asthma with status asthmaticus
J45.42 is a billable, specific ICD-10-CM code for moderate persistent asthma with status asthmaticus. It is valid for submission on a claim.
Excludes1 inherited from the categories above J45.42
These are not written on J45.42, but they bind it: a note on a category applies to every code beneath it. Billing J45.42 with anything listed here is a denial.
Excludes2 inherited from the categories above J45.42
Also inherited, and the opposite of Excludes1: these conditions are not part of J45.42, but a patient can have both, so you may code both.
Other codes that can never be billed with J45.42
These codes carry an Excludes1 note pointing at J45.42. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading J45.42 alone.
Risk adjustment
J45.42 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
J45.42 is named in 56 Medicare coverage policies — 54 listing it as supporting medical necessity, and 2 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56566Billing and Coding: Outpatient Physical and Occupational Therapy Servicesnot covered
- A57067Billing and Coding: Outpatient Physical and Occupational Therapy Servicesnot covered
- A52448Billing and Coding: Omalizumab and biosimilar, OMLYCLO® (omalizumab-igec)
- A52466Nebulizers - Policy Article
How J45.42 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to J45.42.
- Asthma, asthmatic›moderate persistent›with›status asthmaticus
- Asthma, asthmatic›persistent›moderate›with›status asthmaticus
Code history
J45.42 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.
Related codes at this level
Codes that share J45.4. If J45.42 is not quite right, the correct code is usually one of these.
Questions about J45.42
- Is J45.42 a billable ICD-10-CM code?
- Yes. J45.42 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does J45.42 sit in the tabular list?
- Diseases of the respiratory system (J00-J99), in the block Chronic lower respiratory diseases (J40-J4A).
- What cannot be coded together with J45.42?
- J45.42 carries Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter. Some are written on the categories above J45.42 (J45) and apply to it just the same.