2027 ICD-10-CM Diagnosis Code J4A.9Chronic lung allograft dysfunction, unspecified

ICD-10-CM Codes›J00–J99›J40-J4B›J4A

ICD-10-CM J4A.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

J4A.9 is a billable ICD-10-CM diagnosis code for chronic lung allograft dysfunction, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 190 through 192. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chronic obstructive pulmonary disease and bronchiectasis; and Complication of transplanted organs or tissue, initial encounter.

For Medicare Advantage risk adjustment, J4A.9 maps to CMS-HCC Category 276 (Lung Transplant Status/Complications) under the V28 model, adding a risk factor of about 2.531 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
J4A.9
Billable Status
Yes — Valid for Submission
Code Describes
Chronic lung allograft dysfunction, unspecified
Short Description
Chronic lung allograft dysfunction, unspecified
Same as the full description in the CMS dataset.
Parent Code
J4A
Chronic lung allograft dysfunction

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ40-J4BChronic lower respiratory diseases
CategoryJ4AChronic lung allograft dysfunction
This CodeJ4A.9Chronic lung allograft dysfunction, unspecified

Medicare Risk Adjustment (HCC)Billing

J4A.9 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 2027.

CMS-HCC V28 Category (Payment Model)
HCC 276— Lung Transplant Status/Complications
Payment HCC · PY 2027 one of 17 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+2.531
community, non-dual, aged · ranges 1.277–3.085 across segments
Hierarchy
Supersedes HCC 277, HCC 278, HCC 279, and HCC 280
less severe related categories are not paid alongside HCC 276
Prior Model (CMS-HCC V24)
HCC 186
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 186 · ESRD (V21): HCC 186 · ESRD (V24): HCC 186
ESRD V21 weights: 0.154 dialysis, 0.075 functioning graft · ESRD V24 weights: 0.138 dialysis, 0.000 functioning graft
Part D (RxHCC)
RxHCC 396 — Heart, Lung, Liver, Intestine, or Pancreas Transplant Status
also risk-adjusts in the Part D prescription drug model (V08)

Source: CMS Payment Year 2027 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.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to J4A.9: its own notes plus those printed at J4A, block J40-J4B, and Chapter 10. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block J40-J4B Chronic lower respiratory diseases applies to 40 codes
  • bronchitis due to chemicals, gases, fumes and vapors (J68.0)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block J40-J4B Chronic lower respiratory diseases applies to 40 codes
From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • smoke inhalation (T59.81-)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Code First

The underlying condition named in the note is sequenced before this code.

From J4A Chronic lung allograft dysfunction applies to 3 codes
  • 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 Code

Add a second code, after this one, to fully describe the condition.

From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • code, where applicable, to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • exposure to tobacco smoke in the perinatal period (P96.81)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From J4A Chronic lung allograft dysfunction applies to 3 codes
  • if applicable, bronchiolitis obliterans syndrome (J44.81)

Notes

General instructions on how these codes are used.

From Chapter 10 (J00-J99) Diseases of the respiratory system applies to 366 codes
  • When a respiratory condition is described as occurring in more than one site and is not specifically indexed, it should be classified to the lower anatomic site (e.g. tracheobronchitis to bronchitis in J40).

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name J4A.9, its category, or a range that includes it.

Code Also 1

These codes say J4A.9 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • J44.81 Bronchiolitis obliterans and bronchiolitis obliterans syndrome
    chronic lung allograft dysfunction (J4A.-) names J4A.-, which includes this code

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 RSP008
Chronic obstructive pulmonary disease and bronchiectasis
Default principal diagnosis: inpatient No · outpatient No
CCSR INJ036
Complication of transplanted organs or tissue, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Code History & ChangesHistory

Replacement J4A.9 replaces the following previously assigned code(s):

  • J44.0 - Chr obstructive pulmon disease with (acute) lower resp infct
  • J44.0 - Chronic obstructive pulmon disease w acute lower resp infct
  • J44.1 - Chronic obstructive pulmonary disease w (acute) exacerbation
  • J44.9 - Chronic obstructive pulmonary disease, unspecified
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About J4A.9Overview

What is the ICD-10 code for chronic lung allograft dysfunction, unspecified?

The ICD-10-CM code for chronic lung allograft dysfunction, unspecified is J4A.9 (sometimes written as J4A9). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is J4A.9 (Chronic lung allograft dysfunction) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chronic lung allograft dysfunction, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does J4A.9 group to?

When chronic lung allograft dysfunction, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 192, 190, 191, with relative weights from 0.6285 to 1.0749 depending on complications. Higher weights mean higher Medicare reimbursement.

Can J4A.9 be reported with J68.0?

Not as a rule. The Excludes1 note at block J40-J4B, which applies to J4A.9, lists "bronchitis due to chemicals, gases, fumes and vapors (J68.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

What is coded first with J4A.9?

The Code First note at J4A, which applies to J4A.9, reads: , 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). When one of these applies, it is sequenced before J4A.9.

What HCC is J4A.9?

J4A.9 (chronic lung allograft dysfunction, unspecified) maps to CMS-HCC Category 276 (Lung Transplant Status/Complications), commonly written as HCC 276, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 186 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 396.

Does J4A.9 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, J4A.9 adds a risk adjustment factor of about 2.531 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 1.277 to 3.085 depending on the payment segment). HCC 276 sits at the top of its hierarchy, so no other condition category supersedes it. See the full factor table on the HCC 276 category page.