2026 ICD-10-CM Diagnosis Code J45.50Severe persistent asthma, uncomplicated

ICD-10-CM Codes›J00–J99›J40-J4A›J45

ICD-10-CM J45.50
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

J45.50 is a billable ICD-10-CM diagnosis code for severe persistent 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.

For Medicare Advantage risk adjustment, J45.50 maps to CMS-HCC Category 279 (Severe Persistent Asthma) under the V28 model, adding a risk factor of about 0.818 for a community, non-dual, aged beneficiary in payment year 2026.

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

Code Identity

ICD-10-CM Code
J45.50
Billable Status
Yes — Valid for Submission
Code Describes
Severe persistent asthma, uncomplicated
Short Description
Severe persistent asthma, uncomplicated
Same as the full description in the CMS dataset.
Parent Code
J45.5
Severe persistent asthma

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ40-J4AChronic lower respiratory diseases
CategoryJ45Asthma
This CodeJ45.50Severe persistent asthma, uncomplicated

Medicare Risk Adjustment (HCC)Billing

J45.50 maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.

CMS-HCC V28 Category (Payment Model)
HCC 279— Severe Persistent Asthma
Payment HCC · PY 2026 one of 3 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.818
community, non-dual, aged · ranges 0.594–0.873 across segments
Hierarchy
Superseded by HCC 276, HCC 277, and HCC 278
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
Not mapped under V24
this diagnosis newly risk-adjusts under the V28 model
Part D (RxHCC)
RxHCC 228 — Severe Persistent Asthma
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Near fatal asthma
  • Severe asthma
  • Severe controlled persistent asthma
  • Severe persistent allergic asthma
  • Severe persistent allergic asthma controlled
  • Severe persistent allergic asthma uncontrolled
  • Severe persistent asthma
  • Severe persistent asthma controlled co-occurrent with allergic rhinitis
  • Severe persistent asthma co-occurrent with allergic rhinitis
  • Severe persistent asthma uncontrolled co-occurrent with allergic rhinitis
  • Severe uncontrolled persistent asthma
  • Uncomplicated asthma
  • Uncomplicated severe persistent asthma
  • Uncontrolled asthma

Tabular List NotesGuidance

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

Inclusion Terms

  • Severe persistent asthma NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

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

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

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 J45.50 to ICD-9-CMHistory

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

ICD-9-CM
493.00 Extrinsic asthma NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
493.10 Intrinsic 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 J45.50Overview

What is the ICD-10 code for severe persistent asthma, uncomplicated?

The ICD-10-CM code for severe persistent asthma, uncomplicated is J45.50 (sometimes written as J4550). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Is J45.50 (Severe persistent asthma) a billable code?

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

What MS-DRG does J45.50 group to?

When severe persistent 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 J45.50?

Under the General Equivalence Mappings, severe persistent asthma, uncomplicated converts to ICD-9-CM 493.00 (extrinsic asthma NOS) and 493.10 (intrinsic asthma NOS). The mapping is approximate, so confirm the match fits the documentation.

What HCC is J45.50?

J45.50 (severe persistent asthma, uncomplicated) maps to CMS-HCC Category 279 (Severe Persistent Asthma), commonly written as HCC 279, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. In the Part D prescription drug model it maps to RxHCC 228.

Does J45.50 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, J45.50 adds a risk adjustment factor of about 0.818 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.594 to 0.873 depending on the payment segment). A more severe related category (HCC 276, HCC 277, and HCC 278) supersedes it when both are reported. See the full factor table on the HCC 279 category page.