38 CFR Index for VA Disability Claims

Defines what counts as lay evidence (what a veteran or buddy can attest to from personal knowledge) versus medical evidence requiring a clinician. Veterans are competent to describe symptoms, events, and observable injuries; they are generally not competent to diagnose. Also lays out VA's duty to assist obligation.

Establishes the exposure-period rules for presumptive service connection: Agent Orange (Vietnam, Thailand, Korea DMZ), Gulf War (Southwest Asia), radiation, Camp Lejeune water, and PACT Act burn-pit/airborne hazards. Pairs with § 3.309 (which lists the qualifying conditions).

Lists every condition the VA presumes was caused by qualifying service. § 3.309(e) covers Agent Orange presumptives; § 3.309(f) covers Camp Lejeune; chronic and tropical disease presumptions for other cohorts. If a condition appears here and you meet the § 3.307 exposure period, VA cannot require a nexus letter.

Allows service connection for a non-service condition that is proximately caused or aggravated by an already service-connected condition. The classic examples: sleep apnea secondary to PTSD, hypertension secondary to PTSD, diabetic neuropathy secondary to diabetes. Aggravation claims pay only for the additional disability above the pre-aggravation baseline.

The single regulation that determines back pay. Original claims: date of claim or date entitlement arose, whichever is later. Increased ratings: date of claim, OR up to one year earlier if it is "factually ascertainable" that the disability increased during that window, § 3.400(o)(2). Supplemental claims: date the supplemental was filed (unless filed within one year of an unfavorable decision). CUE, Nehmer, and PACT Act each have their own carve-outs.

Bars the VA from rating the same symptom twice under different diagnostic codes. Pain in the knee cannot be compensated under both the limitation-of-motion code and the arthritis code. But different manifestations of the same underlying condition (back limitation of motion + radiculopathy in the leg) can and must be rated separately. The Esteban three-part test governs.

Pays at the 100% rate when a veteran cannot maintain substantially gainful employment due to service-connected disabilities, even without a 100% schedular rating. Schedular TDIU requires one disability at 60% or a combined 70% with at least one at 40%. Extraschedular TDIU under § 4.16(b) covers veterans who fall outside those thresholds but still cannot work.

A joint with actually painful motion warrants at minimum the compensable rating for that joint, even if range-of-motion measurements alone do not reach the threshold. Combined with DeLuca v. Brown (1995), this is the doctrine that catches knees, shoulders, and backs that hurt under repetition or flare-up but measure within normal limits in a single C&P snapshot.

The 0/10/30/50/70/100 ladder used for every mental-health diagnostic code: PTSD (9411), depressive disorders (9434), generalized anxiety (9400), bipolar (9432), and the rest. Rating is based on overall occupational and social impairment, not symptom checklists alone. The 70% threshold (deficiencies in most areas) is the practical gateway to TDIU consideration.