2027 ICD-10-CM Diagnosis Code J99Respiratory disorders in diseases classified elsewhere
J99 is a billable ICD-10-CM diagnosis code for respiratory disorders 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified lower respiratory disease.
For Medicare Advantage risk adjustment, J99 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
Code EditsBilling
Medicare Code Editor checks that affect claim validity for J99.
Medicare Risk Adjustment (HCC)Billing
J99 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.
- Acute pulmonary African histoplasmosis
- Acute pulmonary histoplasmosis
- African histoplasmosis
- Allergic disorder of respiratory system
- Chronic pulmonary African histoplasmosis
- Chronic pulmonary histoplasmosis
- Disorder of respiratory system co-occurrent with human immunodeficiency virus infection
- Disorder of respiratory system due to microscopic polyangiitis
- Lung disease due to connective tissue disorder
- Lung involvement associated with another disorder
- Necrosis of artery
- Pneumonia caused by Histoplasma
- Pneumonia caused by Histoplasma capsulatum
- Pulmonary African histoplasmosis
- Pulmonary amyloidosis
- Pulmonary histoplasmosis
- Pulmonary schistosomiasis
- Respiratory disorder with AIDS
- Restrictive lung disease
- Restrictive lung disease due to amyotrophic lateral sclerosis
- Restrictive lung disease due to Parkinson disease
- Restrictive lung mechanics due to neuromuscular disease
- Vasculitis due to systemic disease
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to J99: its own notes plus those printed at 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.
- respiratory disorders in:
- amebiasis (A06.5)
- blastomycosis (B40.0-B40.2)
- candidiasis (B37.1)
- coccidioidomycosis (B38.0-B38.2)
- cystic fibrosis with pulmonary manifestations (E84.0)
- dermatomyositis (M33.01, M33.11)
- histoplasmosis (B39.0-B39.2)
- late syphilis (A52.72, A52.73)
- polymyositis (M33.21)
- Sjögren syndrome (M35.02)
- systemic lupus erythematosus (M32.13)
- systemic sclerosis (M34.81)
- Wegener's granulomatosis (M31.30-M31.31)
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 First
The underlying condition named in the note is sequenced before this code.
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 J99, its category, or a range that includes it.
Use Additional Code 1
These codes say to use an additional code from the note, and J99 is one of the codes named.
- E88.02 Plasminogen deficiencyrespiratory disorder related to plasminogen deficiency (J99)
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Lung Diseases
When you breathe, your lungs take in oxygen from the air and deliver it to the bloodstream. The cells in your body need oxygen to work and grow. During a normal day, you breathe nearly 25,000 times. People with lung disease have difficulty breathing. Millions of people in the U.S. have lung disease.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert J99 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About J99Overview
What is the ICD-10 code for respiratory disorders in diseases classified elsewhere?
The ICD-10-CM code for respiratory disorders in diseases classified elsewhere is J99. It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is J99 (Respiratory disorders in diseases classified elsewhere) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report respiratory disorders in diseases classified elsewhere on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does J99 group to?
On inpatient claims, respiratory disorders 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 J99 be a principal diagnosis?
No. This is a manifestation code: respiratory disorders in diseases classified elsewhere describes the manifestation of an underlying disease rather than the disease itself, so the underlying condition is sequenced first.
Can J99 be reported with A06.5?
Not as a rule. The Excludes1 note on J99 lists "amebiasis (A06.5)". 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 J99?
J99 (respiratory disorders in diseases classified elsewhere) 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 J99 risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, J99 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.
