Chronic Respiratory Failure

DC 6604Respiratory38 CFR 4.97, DC 6604

A severe condition where your lungs can no longer adequately exchange oxygen and carbon dioxide, requiring supplemental oxygen or mechanical ventilation. Often the end-stage of other service-connected respiratory conditions. The VA rates chronic respiratory failure based on objective measurements of lung function and oxygen requirements.

How the VA rates this condition

The VA rates this condition based on objective clinical measurements and test results. The examiner will use standardized tests or lab values to determine the severity of your condition rather than relying primarily on subjective symptom reports.

Diagnostic code

DC 6604

Rating range

60% – 100%

Rating levels

Rating criteria are defined in 38 CFR 4.97, DC 6604. This guide presents a plain-language summary and is not a substitute for the full regulatory text. Always consult a VSO or VA-accredited attorney for case-specific advice.

Rating Levels

Your lung function tests show FEV-1 less than 40 percent predicted, or FEV-1/FVC less than 40 percent, or DLCO (SB) less than 40 percent predicted, or you require outpatient oxygen therapy, or you have cor pulmonale, pulmonary hypertension, or recurrent episodes of acute respiratory failure.

What the VA looks for

FEV-1 less than 40% predicted
DLCO (SB) less than 40% predicted
Outpatient oxygen therapy prescribed
Cor pulmonale or right ventricular hypertrophy
Pulmonary hypertension on echocardiogram
Recurrent episodes of acute respiratory failure
Arterial blood gas showing chronic hypoxemia or hypercapnia

Common Pitfalls

⚠Not obtaining arterial blood gas (ABG) testing — ABG results showing chronic hypoxemia (low oxygen) or hypercapnia (high CO2) provide objective evidence of respiratory failure beyond standard PFTs.
⚠Not documenting supplemental oxygen requirements — outpatient oxygen therapy automatically qualifies for 100%. Bring your oxygen prescription, flow rate, and hours of daily use.
⚠Not filing for secondary conditions — chronic respiratory failure commonly causes pulmonary hypertension, right heart failure, depression, and sleep disturbance, each of which may warrant separate service connection.
⚠Not connecting to the underlying service-connected respiratory condition — respiratory failure is often secondary to COPD, asthma, or toxic exposure-related lung disease. Establish the causal chain.

Related DBQ Forms

DBQ Respiratory Conditions (other than Tuberculosis and Sleep Apnea)

View evidence checklist →See secondary conditions →

Condition Rating Guides

Understand what the VA looks for at each rating level — loading conditions…

Chronic Respiratory Failure

How the VA rates this condition

Diagnostic code

DC 6604

Rating range

60% – 100%

Rating levels

Rating Levels

What the VA looks for

FEV-1 less than 40% predicted
DLCO (SB) less than 40% predicted
Outpatient oxygen therapy prescribed
Cor pulmonale or right ventricular hypertrophy
Pulmonary hypertension on echocardiogram
Recurrent episodes of acute respiratory failure
Arterial blood gas showing chronic hypoxemia or hypercapnia

Common Pitfalls

⚠Not obtaining arterial blood gas (ABG) testing — ABG results showing chronic hypoxemia (low oxygen) or hypercapnia (high CO2) provide objective evidence of respiratory failure beyond standard PFTs.

⚠Not documenting supplemental oxygen requirements — outpatient oxygen therapy automatically qualifies for 100%. Bring your oxygen prescription, flow rate, and hours of daily use.

⚠Not filing for secondary conditions — chronic respiratory failure commonly causes pulmonary hypertension, right heart failure, depression, and sleep disturbance, each of which may warrant separate service connection.

⚠Not connecting to the underlying service-connected respiratory condition — respiratory failure is often secondary to COPD, asthma, or toxic exposure-related lung disease. Establish the causal chain.