---
title: "DC 6600 - Bronchitis, chronic:"
diagnostic_code: "6600"
body_system: "Respiratory System"
cfr_section: "§ 4.97"
canonical: "https://veteranai.co/va-rating-schedule/respiratory/6600-chronic-bronchitis"
source: "https://www.ecfr.gov/current/title-38/section-4.97"
updated: "2026-07-21T18:19:58.473129Z"
---

# DC 6600 - Bronchitis, chronic:

Rated under § 4.97. Body system: Respiratory System.

## Rating criteria

| Rating | Criteria |
| --- | --- |
| 100% | FEV-1 less than 40 percent of predicted value, or; the ratio of Forced Expiratory Volume in one second to Forced Vital Capacity (FEV-1/FVC) less than 40 percent, or; Diffusion Capacity of the Lung for Carbon Monoxide by the Single Breath Method (DLCO (SB)) less than 40-percent predicted, or; maximum exercise capacity less than 15 ml/kg/min oxygen consumption (with cardiac or respiratory limitation), or; cor pulmonale (right heart failure), or; right ventricular hypertrophy, or; pulmonary hypertension (shown by Echo or cardiac catheterization), or; episode(s) of acute respiratory failure, or; requires outpatient oxygen therapy |
| 60% | FEV-1 of 40- to 55-percent predicted, or; FEV-1/FVC of 40 to 55 percent, or; DLCO (SB) of 40- to 55-percent predicted, or; maximum oxygen consumption of 15 to 20 ml/kg/min (with cardiorespiratory limit) |
| 30% | FEV-1 of 56- to 70-percent predicted, or; FEV-1/FVC of 56 to 70 percent, or; DLCO (SB) 56- to 65-percent predicted |
| 10% | FEV-1 of 71- to 80-percent predicted, or; FEV-1/FVC of 71 to 80 percent, or; DLCO (SB) 66- to 80-percent predicted |

# Chronic Bronchitis (VA Diagnostic Code 6600)

## Understanding Your Respiratory Rating

Chronic bronchitis is a condition affecting the **Respiratory System**, rated by the VA under **38 CFR § 4.97**, Diagnostic Code **6600**.

The VA assigns a disability rating based largely on the results of pulmonary (lung) function testing and related clinical findings. These measurements help show how well your lungs are moving air and transferring oxygen.

---

## Available Rating Levels

The VA uses the following rating levels for chronic bronchitis:

### 100%
Assigned when any of the following are shown:
- FEV-1 **less than 40%** of predicted value, **or**
- FEV-1/FVC ratio **less than 40%**, **or**
- DLCO (SB) **less than 40%** predicted, **or**
- Maximum exercise capacity **less than 15 ml/kg/min** oxygen consumption (with cardiac or respiratory limitation), **or**
- Cor pulmonale (right heart failure), **or**
- Right ventricular hypertrophy, **or**
- Pulmonary hypertension (shown by echocardiogram or cardiac catheterization), **or**
- Episode(s) of acute respiratory failure, **or**
- Requires outpatient oxygen therapy

### 60%
Assigned when any of the following are shown:
- FEV-1 of **40% to 55%** predicted, **or**
- FEV-1/FVC of **40% to 55%**, **or**
- DLCO (SB) of **40% to 55%** predicted, **or**
- Maximum oxygen consumption of **15 to 20 ml/kg/min** (with cardiorespiratory limit)

### 30%
Assigned when any of the following are shown:
- FEV-1 of **56% to 70%** predicted, **or**
- FEV-1/FVC of **56% to 70%**, **or**
- DLCO (SB) of **56% to 65%** predicted

### 10%
Assigned when any of the following are shown:
- FEV-1 of **71% to 80%** predicted, **or**
- FEV-1/FVC of **71% to 80%**, **or**
- DLCO (SB) of **66% to 80%** predicted

---

## What the VA Looks For

When rating chronic bronchitis, the VA focuses on measurable results from pulmonary function testing, including:

- **FEV-1** — Forced Expiratory Volume in one second, expressed as a percentage of the predicted value
- **FEV-1/FVC** — The ratio of Forced Expiratory Volume in one second to Forced Vital Capacity
- **DLCO (SB)** — Diffusion Capacity of the Lung for Carbon Monoxide by the Single Breath Method, expressed as a percentage of predicted

At the highest rating level, the VA also considers **maximum exercise/oxygen consumption capacity** and serious clinical findings such as **cor pulmonale, right ventricular hypertrophy, pulmonary hypertension, acute respiratory failure, and the need for outpatient oxygen therapy**.

Because more than one measurement can qualify for a given level, the VA generally considers whichever findings apply to your condition.

Source: https://www.ecfr.gov/current/title-38/section-4.97