2026 ICD-10-CM Diagnosis Code R94.2Abnormal results of pulmonary function studies
ICD-10-CM Codes›R00–R99›R90-R94›R94
- Billable — Valid for Submission
- Not Chronic
R94.2 is a billable ICD-10-CM diagnosis code for abnormal results of pulmonary function studies. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 205 through 206. As a symptom code, it should not be used as a principal diagnosis once a related definitive diagnosis has been established. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Abnormal findings without diagnosis.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormal airflow
- Abnormal blood oxygen pressure
- Abnormal distribution of ventilation
- Decreased blood oxygen pressure
- Decreased Bohr effect
- Decreased diffusion capacity of lung
- Decreased forced expiratory volume
- Decreased functional residual capacity
- Decreased maximal voluntary ventilation
- Decreased peak expiratory flow rate
- Decreased respiratory function
- Decreased total lung capacity
- Decreased vital capacity
- Diffusion capacity of lung above reference range
- FEV1/FVC < 70 percent of predicted
- FEV1/FVC > 70 percent of predicted
- FEV1/FVC ratio abnormal
- Finding of diffusion capacity of lung
- Forced expired volume - finding
- Forced vital capacity - finding
- Forced vital capacity below reference range
- FVC - forced vital capacity abnormal
- High airway pressure
- Increased blood oxygen pressure
- Increased Bohr effect
- Increased forced expiratory volume
- Increased functional residual capacity
- Increased maximal voluntary ventilation
- Increased peak expiratory flow rate
- Lung function restrictive
- Lung function significantly obstructed
- Lung function testing abnormal
- Lung volume test abnormal
- Peak expiratory flow rate - compliance moderate
- Peak expiratory flow rate - compliance poor
- Peak expiratory flow rate - finding
- Peak expiratory flow rate - technique moderate
- Peak expiratory flow rate - technique poor
- Peak flow rate - finding
- Peak flow rate abnormal
- Pendelluft
- Regional ventilation differences
- Regional ventilation differences due to gravity
- Regional ventilation differences due to local airway resistance
- Regional ventilation differences due to pleural pressure
- Regional ventilation differences due to unequal bronchial pathway lengths
- Regional ventilation differences due to unequal compliance
- Regional ventilation differences due to unequal stress
- Respiratory flow rate abnormal
- Respiratory flow rate above reference range
- Respiratory flow rate below reference range
- Respiratory quotient - finding
- Respiratory quotient abnormal
- Serial peak expiratory flow rate abnormal
- Spirometry reversibility finding
- Spirometry reversibility positive
- Vital capacity - finding
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Inclusion Terms
- Reduced ventilatory capacity
- Reduced vital capacity
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
- Abnormal, abnormality, abnormalities - See Also: Anomaly;
- pulmonary - R94.2
- test results - R94.2
- vital capacity - R94.2
- Findings, abnormal, inconclusive, without diagnosis - See Also: Abnormal;
- Reduced
- ventilatory or vital capacity - R94.2
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Abnormal, abnormality, abnormalities
- function studies
- pulmonary
- Abnormal, abnormality, abnormalities
- pulmonary
- test results
- Diminished, diminution
- vital capacity
- Findings, abnormal, inconclusive, without diagnosis
- function study NEC
- pulmonary
- Findings, abnormal, inconclusive, without diagnosis
- scan NEC
- lung
- Reduced
- ventilatory or vital capacity
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 R94.2 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About R94.2Overview
Is R94.2 (Abnormal results of function studies) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report abnormal results of pulmonary function studies on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does R94.2 group to?
When abnormal results of pulmonary function studies is the principal diagnosis on an inpatient stay, it groups to MS-DRG 205, 206, with relative weights from 0.9411 to 1.8310 depending on complications. Higher weights mean higher Medicare reimbursement.
Can R94.2 be a principal diagnosis?
Use it with care. This is a symptom code, so once a definitive diagnosis explaining the abnormal results of pulmonary function studies is established, that condition takes the principal position instead.
What is the ICD-9 equivalent of R94.2?
Under the General Equivalence Mappings, abnormal results of pulmonary function studies converts to ICD-9-CM 794.2 (abn pulmonary func study). The mapping is a direct match.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
