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Constrictive Bronchiolitis (Obliterative Bronchiolitis) VA Disability Rating

Diagnostic code 6600
By the editorial deskUpdated Jun 13, 2026Sources verified Jun 13, 2026
Presumptive under: PACT Act
Quick summary
Constrictive bronchiolitis does not yet have its own diagnostic code, so VA rates it by analogy, usually under the respiratory formula at diagnostic code 6600, from 10 to 100 percent based on pulmonary function testing. It is on the PACT Act presumptive list for veterans with qualifying burn pit era service. VA has announced rulemaking to give it a dedicated code.
Key requirements
  • Service connection requires a current diagnosis, an in-service event or exposure, and a medical link (nexus) between the two.
  • VA assigns ratings of 10% to 100% under diagnostic code 6600, using the criteria in the rating table below.
  • The percentage assigned turns on Pulmonary function testing results.
  • Measured at the C&P exam: Pulmonary function test.
  • Presumptive service connection may apply under the PACT Act for veterans with qualifying service.
VA also uses diagnostic code 6600 for Chronic Bronchitis. Those are distinct conditions with their own pages. This page covers Constrictive Bronchiolitis (Obliterative Bronchiolitis) specifically.
This page explains common evidence VA may consider when rating this condition. It is not medical advice and does not diagnose any condition. Talk with a licensed medical professional about diagnosis and treatment, and with a VA accredited representative (38 CFR 14.629) about a specific claim.
Ratings
10% to 100%
Diagnostic code
6600
Decided on
Pulmonary function testing results
Measured by
Pulmonary function test
The five parts of a compensation decisionA current disabilityAn in service eventA connectionSeverity under the criteriaAn effective dateHow the pieces fit together
RatingCriteria
10%FEV-1 71 to 80 percent predicted, or FEV-1/FVC 71 to 80, or DLCO 66 to 80 percent predicted.
30%FEV-1 56 to 70 percent predicted, or FEV-1/FVC 56 to 70, or DLCO 56 to 65 percent predicted.
60%FEV-1 40 to 55 percent predicted, or FEV-1/FVC 40 to 55, or DLCO 40 to 55 percent predicted, or maximum oxygen consumption of 15 to 20 ml/kg/min.
100%FEV-1 less than 40 percent predicted, or FEV-1/FVC less than 40, or DLCO less than 40 percent predicted, or cor pulmonale, right heart failure, pulmonary hypertension, episodes of acute respiratory failure, or outpatient oxygen therapy required.
Rule: 38 CFR 4.97, DC 6600Source: eCFR, Title 38 Part 4Verified: 2026-06-13Change history: no criteria change recorded since publicationEach percentage links to itself; cite with the anchor.

Illustrative scenarios showing how the criteria above are applied. These are educational examples, not a prediction of any individual veteran's rating.

Mild reduction on breathing tests

Illustrates 10%

Situation. PFTs show FEV-1 at about 75 percent of predicted.

How the criteria apply. FEV-1 of 71 to 80 percent predicted, FEV-1/FVC of 71 to 80, or DLCO of 66 to 80 percent predicted rates 10 percent under DC 6600.

Moderate reduction on breathing tests

Illustrates 30%

Situation. PFTs show FEV-1 at about 60 percent of predicted.

How the criteria apply. FEV-1 of 56 to 70 percent predicted, FEV-1/FVC of 56 to 70, or DLCO of 56 to 65 percent predicted rates 30 percent under DC 6600.

How this is usually measured. Most lung conditions are rated from a pulmonary function test, also called a PFT or spirometry. The test records values such as FEV-1, FVC, the FEV-1 to FVC ratio, and DLCO. Under 38 CFR 4.96, the rating is generally read from the post bronchodilator results unless the report explains why those cannot be used. If a decision relied on a general description of your breathing rather than the actual test numbers, that is worth a closer look. Read 38 CFR 4.96

The rating runs on your breathing test numbers. One catch specific to this disease: standard breathing tests can look near normal even when a lung biopsy proves the damage, so push for full testing including DLCO and exercise capacity.

What VA looks at

Pulmonary function testing (FEV-1, FEV-1/FVC, DLCO), how the diagnosis was made (high resolution CT or lung biopsy), and qualifying service for the PACT Act presumption.

Common exam and DBQ topics

Shortness of breath with exertion, cough, exercise tolerance, oxygen use, treatments tried.

Evidence that usually matters

PFT reports, high resolution CT or biopsy results, pulmonology notes, deployment records showing service in a qualifying location.

Common misunderstandings

Standard spirometry can be normal in biopsy proven constrictive bronchiolitis. If your numbers look fine but you cannot pass a fitness test you used to pass, the full workup matters. The condition is presumptive under the PACT Act, so qualifying service replaces the need to prove the exposure caused it.

If a VA decision on this came back wrong

You have three review lanes, pick the one that fits the situation.

Under the Appeals Modernization Act (38 CFR 3.2500), a Higher Level Review or a Board Appeal must be requested within one year of the decision notice. A Supplemental Claim can generally be filed at any time after the decision, but filing any of the three within that one year window is what keeps the claim continuously pursued and protects the original effective date; wait longer and a later award may start from the new filing date instead.

Related conditions

Background reading

Supplemental articles that connect to this condition.

VA Presumptive Conditions, Category by Category

VA recognizes that certain illnesses are presumed service connected for veterans with qualifying service in specific times, places, or duty assignments. This guide walks every active presumptive category, what it covers, and the rule cites.

The C&P Exam: What to Expect and How to Prepare

A Compensation and Pension exam gathers the facts VA needs to rate a claim. Here is who runs it, why VA orders one, how to prepare, what to say about your worst days and flare-ups, what happens if you miss it, and how to read the report.

PACT Act and Gulf War Claims

The PACT Act expanded presumptive conditions for veterans exposed to burn pits and other toxins. Gulf War veterans have separate presumptive rules.

Appealing or Continuing a VA Decision: The Three Lanes Under the AMA

Since Feb 19, 2019, a veteran who disagrees with a VA decision picks from three review lanes: Higher Level Review, Supplemental Claim, or Board Appeal. This is a Walkthrough what each lane is, what it requires, what it costs in time, and how to keep your effective date protected.

The Airborne Hazards Registry, the 2006 Balad Memo, and What Each Does for Your Claim

The VA Airborne Hazards and Open Burn Pit Registry, a Public Law 112-260 program, lets eligible deployers document their exposures and get a free clinical evaluation. The 2006 Curtis and Elliott memo is the contemporaneous Air Force document that warned commanders the Balad burn pit was an acute health hazard. Here is what each one is, what it does, and what it does not do.

Burn Pit Respiratory Conditions: The PACT Act Rating Guide

The PACT Act presumes burn pit exposure and service connection for asthma, rhinitis, sinusitis, COPD, constrictive bronchiolitis, and more, manifesting to any degree at any time. Here is who qualifies, how each condition is rated under 38 CFR 4.97, and the analogous rating trap in the signature burn pit disease.

State benefits stack with VA disability

Your rating may also qualify you for state-level benefits.

VA compensation is federal, but every state layers its own benefits on top. Many states reduce or waive property tax for disabled veterans, and many offer license, tuition, or vehicle benefits at various rating levels. The thresholds, dollar amounts, and eligibility rules vary widely from state to state, so the reliable answer is always your own state's guide.

See your state's benefitsReviewed quarterly

Put this rating to work

Free calculators and a guide to turn a rating percentage into real numbers. Your figures stay on your device unless you ask us to email an estimate.

Secondary conditions and case specific outcomes are fact specific. We do not tell you what claims to file. Consider talking with a VA accredited representative.
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Editor's note

Most recent human review on this page, July 5, 2026. Below is the review history across this page, its citations, and the supplemental articles it links to.

  1. July 5, 2026articleThe Airborne Hazards Registry, the 2006 Balad Memo, and What Each Does for Your Claim
  2. July 5, 2026articleAppealing or Continuing a VA Decision: The Three Lanes Under the AMA
  3. July 5, 2026articlePACT Act and Gulf War Claims
  4. July 5, 2026articleThe C&P Exam: What to Expect and How to Prepare
  5. July 5, 2026articleVA Presumptive Conditions, Category by Category
  6. June 13, 2026conditionThis page
Printed from The Veteran Benefit Desk, https://veteranbenefitdesk.com/conditions/constrictive-bronchiolitis. Figures reflect this page as published. Rates change each December; confirm current amounts at veteranbenefitdesk.com before relying on them.
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