Last verified: APR 22, 2026

VA Claims Glossary

Definitions of key terms used in VA disability claims, rating criteria, and benefits administration. All definitions reference the governing section of 38 CFR where applicable.

Glossary terms

38 CFR38 CFR Parts 3–4
Title 38 of the Code of Federal Regulations — the federal rules governing VA disability compensation, rating criteria, and eligibility. Part 3 covers adjudication procedures; Part 4 is the VA Schedule for Rating Disabilities (VASRD).
Diagnostic Code (DC)38 CFR Part 4, Subpart B
A numeric identifier (e.g., DC 9411 for PTSD, DC 8100 for migraines) assigned by the VA to each ratable medical condition under 38 CFR Part 4. Each diagnostic code specifies the rating tiers and the clinical criteria for each tier.Browse all diagnostic codes →
Combined Rating38 CFR § 4.25
The VA's method of combining multiple disability ratings using "whole person" theory — meaning each successive rating is applied to the remaining non-disabled portion of the whole person. For example, 50% + 30% = 65%, not 80%. Governed by 38 CFR § 4.25.Calculate a combined rating →
Secondary Service Connection38 CFR § 3.310
A disability caused or permanently aggravated by an already service-connected condition. Established under 38 CFR § 3.310. The veteran must show a medical nexus linking the secondary condition to the primary service-connected disability.Explore secondary condition pairings →
TDIU38 CFR § 4.16
Total Disability based on Individual Unemployability — allows veterans rated below 100% schedular to receive compensation at the 100% rate if they cannot maintain substantially gainful employment. The single-disability threshold is 60%; the combined-disability threshold is 70% (with one disability at 40%+). Extraschedular TDIU under § 4.16(b) is available when standard thresholds are not met.TDIU and compensation rates →
SMC38 CFR §§ 3.350–3.352
Special Monthly Compensation — additional payments above the standard schedular rate for severe disabilities such as loss of use of limbs, blindness, loss of a creative organ (SMC-K), or the need for regular aid and attendance. SMC rates are set by statute and can significantly exceed the 100% schedular rate.
ITF38 CFR § 3.155
Intent to File — a preliminary claim that establishes an effective date, protecting the veteran's potential back pay for up to one year while they gather medical evidence and prepare the formal claim. Filed via VA Form 21-0966 or by phone.
C&P Exam
Compensation and Pension examination — the medical evaluation conducted by a VA-contracted examiner to assess the current severity of a disability and assign a rating. The examiner uses a Disability Benefits Questionnaire (DBQ) specific to the body system. The C&P exam is often the single most important piece of evidence in the rating decision.
BDD
Benefits Delivery at Discharge — a VA program that allows service members to file disability claims 180 to 90 days before separation. A completed BDD claim is processed before discharge, meaning the veteran can receive compensation shortly after leaving service rather than waiting months for a post-separation decision.
VASRD38 CFR Part 4
VA Schedule for Rating Disabilities — the complete rating schedule codified in 38 CFR Part 4, organized by body system. The VASRD lists every diagnostic code, the associated rating tiers, and the clinical criteria for each tier. It is the authoritative source the VA uses to assign every disability rating.Browse the VASRD by body system →
Nexus Letter
A medical opinion letter from a qualified healthcare provider establishing a causal connection — or "nexus" — between a veteran's current disability and their military service (direct service connection) or an existing service-connected condition (secondary service connection). A strong nexus letter uses the standard "at least as likely as not" (50%+ probability) threshold.
Bilateral Factor38 CFR § 4.26
An additional compensation calculation applied when a veteran has ratable disabilities affecting both arms, both legs, or paired extremities. The bilateral factor adds 10% of the combined value of those ratings before the result is combined with other disabilities. Governed by 38 CFR § 4.26.
Effective Date38 CFR § 3.400
The date from which VA compensation is paid. Generally, this is the date the VA receives the claim or the date entitlement arose — whichever is later. Filing an Intent to File (ITF) can preserve an effective date up to one year before the formal claim is submitted.
COLA
Cost of Living Adjustment — an annual increase to VA compensation and pension rates, typically effective December 1 and calculated based on the Consumer Price Index (CPI-W). COLA adjustments are mandated by statute and mirror Social Security COLA increases.2026 VA compensation rates →
BAH
Basic Allowance for Housing — a non-taxable monthly allowance paid to active-duty service members (and in some cases veterans in certain education programs) to offset the cost of housing. BAH rates are set annually by DoD and vary by pay grade, dependency status, and the military housing area (MHA) of the duty station.2026 BAH rates by location →

Common Questions About VA Claims Terminology

What is the difference between a combined rating and a total rating?

A combined rating applies the VA's "whole person" method, where each successive disability is applied to the remaining non-disabled percentage. A total rating means the veteran has a schedular 100% rating based on a single disability or combination. TDIU allows veterans below 100% schedular to receive 100% compensation if unemployability criteria are met under 38 CFR § 4.16.

What is the standard of evidence for secondary service connection?

Under 38 CFR § 3.310, the veteran must show that the secondary disability was caused or permanently aggravated by the primary service-connected condition. The required medical standard is "at least as likely as not" — a 50% or greater probability — established through a nexus letter or VA examination.

How does the VA use diagnostic codes in rating decisions?

Each diagnostic code in 38 CFR Part 4 specifies the clinical criteria for each rating tier (e.g., 0%, 10%, 30%, 50%, 70%, 100%). The C&P examiner's findings are compared against those criteria to assign the appropriate tier. Analogous ratings under 38 CFR § 4.20 allow the VA to rate unlisted conditions by analogy to the most similar listed condition.

Can a veteran file for TDIU if they are already at 90% combined?

Yes. A veteran with a 90% combined rating who has one disability at 60%+ (or two disabilities totaling 70% with one at 40%+) meets the schedular TDIU thresholds under 38 CFR § 4.16(a). If they cannot maintain substantially gainful employment due to service-connected disabilities, they are entitled to 100% compensation without a schedular 100% rating.

What is the significance of an Intent to File (ITF)?

An ITF under 38 CFR § 3.155 establishes a protective effective date. If the veteran subsequently files a complete claim within one year of the ITF, any granted benefits are paid retroactively to the ITF date — not the later date the formal claim was submitted. This can mean months of additional back pay for veterans who need time to gather evidence.

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