2027 ICD-10-CM Diagnosis Code J84.170Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere

ICD-10-CM Codes›J00–J99›J80-J84›J84

ICD-10-CM J84.170
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

J84.170 is a billable ICD-10-CM diagnosis code for interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 196 through 198. The code is a manifestation code that cannot be reported as the principal diagnosis. Coders also document this condition as pleuroparenchymal fibroelastosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.

For Medicare Advantage risk adjustment, J84.170 maps to CMS-HCC Category 278 (Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis) under the V28 model, adding a risk factor of about 0.818 for a community, non-dual, aged beneficiary in payment year 2027.

Code Identity

ICD-10-CM Code
J84.170
Billable Status
Yes — Valid for Submission
Code Describes
Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere
Short Description
Interstit lung dis w progr fibrotic phenotype dis classd e
Parent Code
J84.17
Other interstitial pulmonary diseases with fibrosis in diseases classified elsewhere

Code Classification

ChapterJ00–J99Diseases of the respiratory system
SectionJ80-J84Other respiratory diseases principally affecting the interstitium
CategoryJ84Other interstitial pulmonary diseases
This CodeJ84.170Interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere

Code EditsBilling

Medicare Code Editor checks that affect claim validity for J84.170.

Manifestation diagnoses
Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

Medicare Risk Adjustment (HCC)Billing

J84.170 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 278— Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis
Payment HCC · PY 2027 one of 4 ICD-10-CM codes in this category
Risk Adjustment Factor (RAF) Weight
+0.818
community, non-dual, aged · ranges 0.650–1.640 across segments
Hierarchy
Superseded by HCC 276 and HCC 277
a more severe related category takes the payment when both are reported
Prior Model (CMS-HCC V24)
HCC 112
V24 retired V28 pays 100% of MA risk scores since PY 2026
Other CMS Models
PACE (CMS-HCC V22): HCC 112 · ESRD (V21): HCC 112 · ESRD (V24): HCC 112
ESRD V21 weights: 0.066 dialysis, 0.281–0.299 functioning graft · ESRD V24 weights: 0.058 dialysis, 0.080–0.256 functioning graft
Part D (RxHCC)
RxHCC 226 — Idiopathic Pulmonary Fibrosis and Systemic Sclerosis with Lung Involvement
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.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pleuroparenchymal fibroelastosis
  • Pleuroparenchymal fibroelastosis due to connective tissue disease
  • Pleuroparenchymal fibroelastosis due to idiopathic pulmonary fibrosis
  • Secondary pleuroparenchymal fibroelastosis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to J84.170: its own notes plus those printed at J84.1, J84, and Chapter 10. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Progressive fibrotic interstitial lung disease

Excludes1

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

From J84.1 Other interstitial pulmonary diseases with fibrosis applies to 10 codes
  • pulmonary fibrosis (chronic) following radiation (J70.1)
From J84 Other interstitial pulmonary diseases applies to 24 codes
  • drug-induced interstitial lung disorders (J70.2-J70.4)
  • interstitial emphysema (J98.2)

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 J84 Other interstitial pulmonary diseases applies to 24 codes
  • lung diseases due to external agents (J60-J70)
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.

  • underlying disease, such as:
  • lung diseases due to external agents (J60-J70)
  • rheumatoid arthritis (M05.00-M06.9)
  • sarcoidosis (D86.-)
  • systemic connective tissue disorders (M30-M36)

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 J84.1 Other interstitial pulmonary diseases with fibrosis applies to 10 codes
  • if applicable, pulmonary fibrosis (chronic) due to inhalation of chemicals, gases, fumes or vapors (J68.4)
From J84 Other interstitial pulmonary diseases applies to 24 codes
  • if applicable, associated condition

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 J84.170, its category, or a range that includes it.

Code Also 1

These codes say J84.170 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • I27.23 Pulmonary hypertension due to lung diseases and hypoxia
    interstitial lung disease (J84.-) names J84.-, 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 RSP016
Other specified and unspecified lower respiratory disease
Default principal diagnosis: inpatient No · outpatient No

Patient EducationClinical

Interstitial Lung Diseases

Interstitial lung disease is the name for a large group of diseases that inflame or scar the lungs. The inflammation and scarring make it hard to get enough oxygen. The scarring is called pulmonary fibrosis.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code History & ChangesHistory

Replacement J84.170 replaces the following previously assigned code(s):

  • J84.17 - Oth interstit pulmon dis w fibrosis in dis classd elswhr
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About J84.170Overview

Is J84.170 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does J84.170 group to?

On inpatient claims, interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere maps to MS-DRG 198, 197, 196, with relative weights from 0.7256 to 1.8335 depending on complications. Higher weights mean higher Medicare reimbursement.

Can J84.170 be a principal diagnosis?

No. This is a manifestation code: interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.

Can J84.170 be reported with J70.1?

Not as a rule. The Excludes1 note at J84.1, which applies to J84.170, lists "pulmonary fibrosis (chronic) following radiation (J70.1)". 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 J84.170?

The Code First note reads: underlying disease, such as: lung diseases due to external agents (J60-J70); rheumatoid arthritis (M05.00-M06.9); sarcoidosis (D86.-); systemic connective tissue disorders (M30-M36). When one of these applies, it is sequenced before J84.170.

What HCC is J84.170?

J84.170 (interstitial lung disease with progressive fibrotic phenotype in diseases classified elsewhere) maps to CMS-HCC Category 278 (Idiopathic Pulmonary Fibrosis and Lung Involvement in Systemic Sclerosis), commonly written as HCC 278, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2027. It mapped to HCC 112 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 226.

Does J84.170 risk-adjust for Medicare Advantage payment?

Yes. When documented and reported on a Medicare Advantage encounter, J84.170 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 0.650 to 1.640 depending on the payment segment). A more severe related category (HCC 276 and HCC 277) supersedes it when both are reported. See the full factor table on the HCC 278 category page.