2027 ICD-10-CM Diagnosis Code J84.9Interstitial pulmonary disease, unspecified
ICD-10-CM Codes›J00–J99›J80-J84›J84
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- Risk Adjusts — HCC 280
- Chronic Condition
J84.9 is a billable ICD-10-CM diagnosis code for interstitial pulmonary disease, unspecified. 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. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 90 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.
For Medicare Advantage risk adjustment, J84.9 maps to CMS-HCC Category 280 (Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders) under the V28 model, adding a risk factor of about 0.319 for a community, non-dual, aged beneficiary in payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
J84.9 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.
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.
- Bronchiolocentric interstitial pneumonia
- Bronchiolocentric interstitial pneumonia due to inhalation of substance
- Chronic interstitial lung disease
- Congenital nephrotic syndrome, interstitial lung disease, epidermolysis bullosa syndrome
- Interstitial lung abnormality
- Interstitial lung disease
- Interstitial lung disease due to and following radiotherapy
- Interstitial lung disease due to collagen vascular disease
- Interstitial lung disease due to connective tissue disease
- Interstitial lung disease due to granulomatous disease
- Interstitial lung disease due to juvenile polymyositis
- Interstitial lung disease due to metabolic disease
- Interstitial lung disease due to systemic disease
- Interstitial lung disease with systemic vasculitis
- Interstitial pneumonia
- Interstitial pneumonitis with autoimmune features
- Nonspecific interstitial pneumonia
- Pulmonary hypertension due to interstitial lung disease
- Pulmonary hypertension due to lung disease and/or hypoxia
- Secondary bronchiolocentric interstitial pneumonia
- Vasculitis due to systemic disease
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to J84.9: its own notes plus those printed at 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.
- Interstitial pneumonia NOS
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- 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 Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
- if applicable, associated condition
Notes
General instructions on how these codes are used.
- 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 J84.9, its category, or a range that includes it.
Excludes1 4
These codes carry an Excludes1 note naming J84.9: they are not reported together with it, unless the two conditions are unrelated.
- J18 Pneumonia, unspecified organisminterstitial pneumonia NOS (J84.9)
- J70.2 Acute drug-induced interstitial lung disordersinterstitial pneumonia NOS (J84.9)
- J70.3 Chronic drug-induced interstitial lung disordersinterstitial pneumonia NOS (J84.9)
- J70.4 Drug-induced interstitial lung disorders, unspecifiedinterstitial pneumonia NOS (J84.9)
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disease, diseased See Also: Syndrome;
interstitial J84.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.
Convert J84.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J84.9Overview
What is the ICD-10 code for interstitial pulmonary disease, unspecified?
The ICD-10-CM code for interstitial pulmonary disease, unspecified is J84.9 (sometimes written as J849). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is J84.9 (Other interstitial pulmonary diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report interstitial pulmonary disease, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does J84.9 group to?
When interstitial pulmonary disease, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 198, 197, 196, with relative weights from 0.7256 to 1.8335 depending on complications. Higher weights mean higher Medicare reimbursement.
Is J84.9 a CC or MCC?
CMS lists J84.9 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 90 closely related codes in its exclusion list.
Can J84.9 be reported with J98.2?
Not as a rule. The Excludes1 note at J84, which applies to J84.9, lists "interstitial emphysema (J98.2)". 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 HCC is J84.9?
J84.9 (interstitial pulmonary disease, unspecified) maps to CMS-HCC Category 280 (Chronic Obstructive Pulmonary Disease, Interstitial Lung Disorders, and Other Chronic Lung Disorders), commonly written as HCC 280, 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 227.
Does J84.9 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, J84.9 adds a risk adjustment factor of about 0.319 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.209 to 0.390 depending on the payment segment). A more severe related category (HCC 276, HCC 277, HCC 278, and HCC 279) supersedes it when both are reported. See the full factor table on the HCC 280 category page.
