Pulmonary Function Tests in VA Disability Claims: PFT and Spirometry Guide

Under 38 CFR 4.97, Pulmonary Function Tests (PFTs) provide the primary objective clinical benchmark for rating chronic lung disabilities. The VA relies on spirometry to evaluate airflow limitation through four key measurements: Forced Expiratory Volume in one second (FEV-1), Forced Vital Capacity (FVC), the FEV-1/FVC percentage ratio, and Diffusing Capacity of the Lung for Carbon Monoxide (DLCO). The rating schedule assigns percentage evaluations based on the degree of deficit demonstrated on testing.

The General Rating Formula for Respiratory Conditions in 38 CFR 4.97 establishes four primary compensable tiers: 10% for an FEV-1 of 71% to 80% predicted, FEV-1/FVC of 71% to 80%, or DLCO of 66% to 80%; 30% for an FEV-1 of 56% to 70% predicted, FEV-1/FVC of 56% to 70%, or DLCO of 56% to 65%; 60% for an FEV-1 of 40% to 55% predicted, FEV-1/FVC of 40% to 55%, or DLCO of 40% to 55%; and 100% for an FEV-1 or DLCO of less than 40% predicted, or FEV-1/FVC less than 40%.

Under 38 CFR 4.96(d), post-bronchodilator studies are generally required when PFTs are performed for VA disability evaluations, and post-bronchodilator results are generally used for rating. However, important regulatory exceptions apply: post-bronchodilator testing is not required if pre-bronchodilator values are normal or the examiner explains why it should not be done; if post-bronchodilator results are poorer than pre-bronchodilator results, the pre-bronchodilator values are used; and when different test results produce different rating levels, the VA uses the value the examiner states most accurately reflects disability.

Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) measures how efficiently oxygen transfers across alveolar capillary membranes into the bloodstream. In restrictive lung disorders such as pulmonary fibrosis, sarcoidosis, asbestosis, or chronic beryllium disease, standard spirometry (FEV-1) may appear relatively normal while DLCO is profoundly reduced. Under 38 CFR 4.97, the VA is required to assign the highest evaluation warranted by any qualifying test parameter, meaning a severe DLCO deficit controls even if FEV-1 is mild.

Under 38 CFR 4.96(d)(1), formal pulmonary function testing is excused and ratings are assigned based on clinical records in several specific circumstances: when a veteran requires continuous outpatient oxygen therapy; when right ventricular hypertrophy, cor pulmonale, or pulmonary hypertension is clinically documented; when a veteran has experienced episodes of acute respiratory failure; or when testing would be medically contraindicated because of acute illness, recent cardiac infarction, or thoracic surgery.