What is ICD-10 code J45.50?

J45.50 is the ICD-10-CM diagnosis code for Severe persistent asthma, uncomplicated. Severe persistent asthma without any current complications or exacerbations. It belongs to the ICD-10-CM chapter for diseases of the respiratory system (j00-j99). J45.50 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. J45.50 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. J45.50 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. J45.50 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does J45.50 map to under V28?

J45.50 maps to CMS-HCC V28 279 (Severe Persistent Asthma). The category number and label come from the CMS-HCC V28 model file for payment year 2026.

What does J45.50 pay in RAF?

J45.50 carries a community, non-dual, aged (CNA) RAF weight of 0.818 under CMS-HCC V28 for payment year 2026. The weight comes from the CMS V28 relative-factor file, not a hand-typed table.

What is the V28 vs V24 difference for J45.50?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. J45.50 is a payment HCC under V28 (Severe Persistent Asthma) but was not retained as a payment HCC under V24. Both models can still appear in legacy data and in payer-specific lookback periods.

What documentation supports J45.50?

Use J45.50 when the provider wording supports severe persistent asthma, uncomplicated. Check the FY2026 tabular notes and the full code path before the final code choice. For this DOS, capture the provider's current assessment and the care action documented for severe persistent asthma, uncomplicated. Keep the checklist tied to the note. Do not swap J45.50 with J45.51. The FY2026 tabular describes J45.51 as severe persistent asthma with (acute) exacerbation. Follow the documented detail. Because J45.50 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score. See the MEAT criteria checklist at /meat-criteria for what Monitor, Evaluate, Assess, or Treat looks like in a note. MEAT is generic documentation evidence, not a payer-specific rule.

2026 ICD-10-CM J45.50: Severe persistent

J45.50 maps to CMS-HCC V28 279 (RAF 0.818). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools

ICD-10-CM Code View

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Code lookupJ45.50Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the respiratory system (J00-J99) / Chronic lower respiratory diseases (J40-J4A)

J45.50

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Severe persistent asthma, uncomplicated

Severe persistent asthma without any current complications or exacerbations.

Buddy Insight

CMS-HCC V28

Mapped

HCC 279

Severe Persistent Asthma

RAF 0.818

CMS-HCC V24

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ACA/HHS

Mapped

HCC 161.1

HHS-HCC 161.1

Varies by metal level

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

Mapped

HCC 228

Severe Persistent Asthma

RAF 0.855

Code Book Path

Official

J45Asthma

J45.5Severe persistent asthma

J45.50Severe persistent asthma, uncomplicated

Inclusion Terms

Official

Severe persistent asthma NOS

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for J45.50 in this effective period.

Related Child Codes

Official

J45.51Severe persistent asthma with (acute) exacerbation

J45.52Severe persistent asthma with status asthmaticus

Includes

Official

ICD-10-CM does not list Includes notes for J45.50 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for J45.50 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for J45.50 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for J45.50 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for J45.50 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Asthma diagnosis with severity explicitly classified as severe persistent by the provider

Symptom frequency: throughout the day, frequent nighttime awakenings (often nightly), extreme limitation of activity

High-dose inhaled corticosteroids plus long-acting beta-agonist, possibly with oral corticosteroids or biologics

Lung function: FEV1 <60% predicted if documented

MEAT Support

HCC Buddy guidance

Asthma diagnosis with severity explicitly classified as severe persistent by the provider

Symptom frequency: throughout the day, frequent nighttime awakenings (often nightly), extreme limitation of activity

High-dose inhaled corticosteroids plus long-acting beta-agonist, possibly with oral corticosteroids or biologics

Lung function: FEV1 <60% predicted if documented

Audit Caution

HCC Buddy guidance

Underclassifying severe persistent asthma as moderate persistent — this significantly impacts V28 HCC mapping (J45.50 maps, J45.40 does not)

Using uncomplicated code during an exacerbation — should be J45.51

Not capturing biologic therapy (omalizumab, mepolizumab, etc.) as supporting evidence of severe persistent classification

Coding severe persistent without supporting documentation of continuous symptoms and severe functional limitation

Common Mistakes

HCC Buddy guidance

J45.40 — Moderate persistent asthma: daily symptoms but not throughout the day; does NOT map to V28 HCC

J45.51 — Severe persistent asthma with acute exacerbation: use during acute worsening of severe asthma

J45.52 — Severe persistent asthma with status asthmaticus: use for treatment-refractory life-threatening attack

J44.9 — COPD, unspecified: different disease; some patients may have asthma-COPD overlap

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is J45.50 an HCC code?

Yes. J45.50 (Severe persistent asthma, uncomplicated) maps to Severe Persistent Asthma under the CMS-HCC V28 risk adjustment model, with a community non-dual aged RAF of 0.818. It is billable for payment year 2026.

Coder answer: J45.50 is billable and maps to V28 HCC 279, Severe Persistent Asthma. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: J45.50
Description: Severe persistent asthma, uncomplicated
HCC (V28): HCC 279 — Severe Persistent Asthma
RAF: 0.818
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 279, Severe Persistent Asthma

0.818

RxHCCHCC 228, Severe Persistent Asthma

0.855

Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

Work J45.50 in the Code Book — tabular path, V28 RAF, and MEAT checklist →

MEAT Criteria for J45.50

For J45.50 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed J45.50 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

J45.50 is the ICD-10-CM diagnosis code for severe persistent asthma, uncomplicated. Severe persistent asthma without any current complications or exacerbations. J45.50 sits in the ICD-10-CM chapter for diseases of the respiratory system (j00-j99), within the section covering chronic lower respiratory diseases (j40-j4a).

Under the CMS-HCC V28 risk adjustment model, J45.50 maps to Severe Persistent Asthma (HCC 279) with a community, non-dual, aged base RAF weight of 0.818. J45.50 was not retained as a payment HCC under the older V24 model, so V28 introduced or recategorized it during the 2024–2026 phase-in. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.

Use J45.50 when the provider wording supports severe persistent asthma, uncomplicated. Check the FY2026 tabular notes and the full code path before the final code choice. Because J45.50 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for J45.50 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use J45.50 when the provider wording supports severe persistent asthma, uncomplicated. Check the FY2026 tabular notes and the full code path before the final code choice.
•For this DOS, capture the provider's current assessment and the care action documented for severe persistent asthma, uncomplicated. Keep the checklist tied to the note.
•Do not swap J45.50 with J45.51. The FY2026 tabular describes J45.51 as severe persistent asthma with (acute) exacerbation. Follow the documented detail.
•J45.50 maps to V28 HCC 279, Severe Persistent Asthma. The mapping does not replace the documentation review. The code still has to match the note.
•Ask Buddy to show the official notes for J45.50 or compare its code path with J45.51.

Clinical Significance

Severe persistent asthma, uncomplicated represents the most serious chronic asthma classification with continuous symptoms throughout the day, frequent nighttime awakenings (often nightly), and extremely limited physical activity. This is a clinically significant condition that maps to V28 HCC, reflecting the substantial ongoing disease burden and resource utilization.

Documentation Requirements

✓Asthma diagnosis with severity explicitly classified as severe persistent by the provider
✓Symptom frequency: throughout the day, frequent nighttime awakenings (often nightly), extreme limitation of activity
✓High-dose inhaled corticosteroids plus long-acting beta-agonist, possibly with oral corticosteroids or biologics
✓Lung function: FEV1 <60% predicted if documented
✓Multiple exacerbations per year or history of near-fatal asthma events
✓Documentation that condition is currently uncomplicated (at baseline, no current exacerbation)

Commonly Confused Codes

•J45.40: Moderate persistent asthma: daily symptoms but not throughout the day; does NOT map to V28 HCC
•J45.51: Severe persistent asthma with acute exacerbation: use during acute worsening of severe asthma
•J45.52: Severe persistent asthma with status asthmaticus: use for treatment-refractory life-threatening attack
•J44.9: COPD, unspecified: different disease; some patients may have asthma-COPD overlap