2026 ICD-10-CM J4A: Chronic lung allograft dysfunction

Log in Start free trial

J4A is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC Buddy coding tools

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupJ4A

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

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

J4A

Header CodeICD-10-CMOfficial ICD-10-CMCodebook guidance

Chronic lung allograft dysfunction

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ACA/HHS

N/A

—

Not risk-adjusted for this model/period.

Not mapped

ESRD/PACE

N/A

—

Not risk-adjusted for this model/period.

Not mapped

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

J4AChronic lower respiratory diseases (J40-J4A)J4AChronic lung allograft dysfunction

Inclusion Terms

Official

No inclusion terms are included in this display for J4A. Check the code and parent instructions in the Code Book.

Excludes 2

Official

certain conditions originating in the perinatal period (P04-P96)Inherited from J00-J99, J40-J4A
certain infectious and parasitic diseases (A00-B99)Inherited from J00-J99, J40-J4A
complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from J00-J99, J40-J4A
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)Inherited from J00-J99, J40-J4A
endocrine, nutritional and metabolic diseases (E00-E88)Inherited from J00-J99, J40-J4A
injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from J00-J99, J40-J4A
neoplasms (C00-D49)Inherited from J00-J99, J40-J4A
smoke inhalation (T59.81-)Inherited from J00-J99, J40-J4A
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from J00-J99, J40-J4A
cystic fibrosis (E84.-)Inherited from J00-J99, J40-J4A

Related Codes

Official

J4A.0Restrictive allograft syndrome J4A.8Other chronic lung allograft dysfunction J4A.9Chronic lung allograft dysfunction, unspecified

Includes

Official

No Includes notes are included in this display for J4A. Check the code and parent instructions in the Code Book.

Excludes 1

Official

bronchitis due to chemicals, gases, fumes and vapors (J68.0)Inherited from J40-J4A

Code First

Official

, if applicable:
heart-lung transplant rejection (T86.31)
lung transplant rejection (T86.810)
other complications of heart-lung transplant (T86.39)
other complications of lung transplant (T86.818)

Use Additional

Official

code, where applicable, to identify:Inherited from J00-J99
exposure to environmental tobacco smoke (Z77.22)Inherited from J00-J99
exposure to tobacco smoke in the perinatal period (P96.81)Inherited from J00-J99
history of tobacco dependence (Z87.891)Inherited from J00-J99
occupational exposure to environmental tobacco smoke (Z57.31)Inherited from J00-J99
tobacco dependence (F17.-)Inherited from J00-J99
tobacco use (Z72.0)Inherited from J00-J99

Code Also

Official

, if applicable, bronchiolitis obliterans syndrome (J44.81)

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 →

Code: J4A
Description: Chronic lung allograft dysfunction
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: No
Payment year: 2026

Coder workflow notes

Get the V28 mapping + MEAT cheat sheet

One printable reference: check representative V28 mappings and the documentation reminders your note needs. Free, no card.

Free PDF. No card. Unsubscribe anytime.

What This Code Means

J4A is the ICD-10-CM diagnosis code for chronic lung allograft dysfunction. J4A 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).

Header codes like J4A cannot be reported on claims directly; they organize child codes that share clinical context. Coders should select the billable child code that matches the documented presentation and then verify its current source-backed HCC mapping. Do not infer a child code or risk adjustment value from the header alone.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for J4A sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Code First

, if applicable:
heart-lung transplant rejection (T86.31)
lung transplant rejection (T86.810)
other complications of heart-lung transplant (T86.39)
other complications of lung transplant (T86.818)

Code Also

, if applicable, bronchiolitis obliterans syndrome (J44.81)

Child Codes

J4A.0Restrictive allograft syndrome

J4A.8Other chronic lung allograft dysfunction

J4A.9Chronic lung allograft dysfunction, unspecified

Code Hierarchy

└J4AChronic lung allograft dysfunction

└J4AChronic lung allograft dysfunction

J4A code history

Code set	Change
FY2024 (effective Oct 1, 2023)	Added to the code set

Source: official CMS ICD-10-CM order and addenda files, FY2016 through FY2027.

More on J4A

Referenced in blog posts

COPD HCC Coding: J44.9 Still Maps to HCC 280

Work J4A in HCC Buddy

Open J4A in the Code Book for the full Index-to-Tabular path, MEAT checklist, and V28 HCC mapping, or in the Encoder to code from a keyword search. Pro includes 7 days to try everything, no card required.

Open in Code Book Open in Encoder Start Pro