The Law Library
The M21-1 manual
The internal playbook regional office raters follow. It tells you what the rater is told to look for. For the full background, read our M21-1 guide.
How much it binds
The M21-1 is the Veterans Benefits Administration's procedures manual, and regional office claims processors follow it, so for most veterans it is effectively the rulebook for the first decision. It is not a regulation, and the Board of Veterans' Appeals is not bound by it: 38 CFR 20.105 says the Board "is not bound by Department manuals, circulars, or similar administrative issues." In Overton v. Wilkie, No. 17-0125 (Vet. App. Sept. 19, 2018), the court held the Board must discuss relevant M21-1 provisions, and before relying on one it must independently review the issue and explain why. On whether courts can review the manual directly: the Federal Circuit first said no, because the manual does not bind the Board (Disabled American Veterans v. Secretary, 859 F.3d 1072 (Fed. Cir. 2017); Gray v. Secretary, 875 F.3d 1102 (Fed. Cir. 2017)). Sitting en banc, it overruled both in National Organization of Veterans' Advocates v. Secretary, No. 2020-1321 (Fed. Cir. Dec. 8, 2020), holding that an M21-1 rule of general applicability that binds the agency's initial adjudicators can be challenged under 38 U.S.C. 502, and noting the manual is effectively the last word for the vast majority of veterans.
M21-1, Part V, Subpart ii, Chapter 1, Section A
Principles of Reviewing and Weighing Evidence
This is how raters are told to weigh evidence. Your evidence only has to make each fact at least as likely as not, and weighing is about how persuasive the evidence is, not a head count of documents. Raters are also told not to treat a missing piece of proof as negative evidence, though a total lack of supporting records can still be considered.
M21-1, Part IV, Subpart i, Chapter 1, Section A
Duty to Assist With Providing a Medical Examination or Opinion
This is the step-by-step version of VA's duty to get you a C&P exam or medical opinion. It explains the regulatory test raters use to decide an exam is needed, and that raters must review the evidence first and document the exam review.
M21-1, Part IV, Subpart i, Chapter 3, Section C
Insufficient Examinations
Lists what makes a C&P exam report insufficient: unsigned, a claimed condition not addressed, required questionnaire items left blank, no file review when one was required, missing functional loss details, or an opinion without a valid rationale. It also covers how raters send a report back for clarification or rework, which gives you specific defects to point to.
M21-1, Part V, Subpart ii, Chapter 2, Section A
Direct Service Connection (SC) and Service Incurrence of an Injury
Covers the basics of direct service connection: a current disability, something in service, and a link between them. It also explains the presumption of soundness at entry, chronic conditions and continuity of symptoms, and how combat evidence is weighed.
M21-1, Part V, Subpart ii, Chapter 2, Section B
Presumptive Service Connection (SC)
Explains how presumptive service connection works, including how a condition is shown to have started inside a required time window. It also covers the evidence VA needs to rebut a presumption, with examples of evidence that is and isn't enough.
M21-1, Part V, Subpart ii, Chapter 2, Section D
Secondary Service Connection (SC) and Aggravation of Non-Service-Connected (NSC) Disabilities
Covers conditions caused or made worse by a disability you're already service connected for. For aggravation, VA needs a baseline showing how severe the other condition was before it got worse, which can come from earlier medical records or other credible evidence, including lay statements.
M21-1, Part V, Subpart ii, Chapter 4, Section A
Effective Dates
The rater's guide to picking a start date: the general rule of the later of the claim date or the date entitlement arose, how an intent to file preserves a date, and the rules for direct, secondary, presumptive, increase, and individual unemployability claims. It also covers retroactive awards after a liberalizing change in the law.
M21-1, Part VIII, Subpart iv, Chapter 3, Section A
General Information on Individual Unemployability (IU) Claims
Sets out what TDIU requires: being unable to secure or follow substantially gainful work because of service-connected disability, plus either the rating thresholds in 38 CFR 4.16(a) or an extra-schedular approval under 4.16(b). Marginal work, including work in a protected setting, doesn't bar TDIU, and the section defines substantially gainful employment using the poverty threshold for one person.
M21-1, Part VIII, Subpart iv, Chapter 4, Section A
Special Monthly Compensation (SMC)
The rater's guide to SMC, the extra monthly payments for things like loss of use of a hand or foot, needing aid and attendance, or being housebound. It covers what to ask the examiner about loss of use, and that raters must address SMC in the rating decision and use VA's SMC calculator.
M21-1, Part VIII, Subpart ii, Chapter 2, Section A
General Information on Claims Based on Exposure to Burn Pits and Other Toxins, Including Fine Particulate Matter (BPOT)
Explains the PACT Act burn pit and toxin presumptions: who counts as a covered veteran, and the conditions presumed service connected under 38 U.S.C. 1120 and the regulations at 38 CFR 3.320a and 3.320b. Start here if you served in Southwest Asia or the other listed locations.
M21-1, Part VIII, Subpart iv, Chapter 1, Section A
General Information and Development for Posttraumatic Stress Disorder (PTSD) Claims
Covers how VA verifies a PTSD stressor. Your own statement can be enough for combat, prisoner of war, or fear of hostile military or terrorist activity stressors when the stressor fits your service and, for the fear category, a VA psychiatrist or psychologist confirms it supports the diagnosis. A buddy statement consistent with both veterans' service is accepted as corroboration.
M21-1, Part VIII, Subpart iv, Chapter 1, Section E
Evidence Evaluation and Decisions for Posttraumatic Stress Disorder (PTSD) Claims Related to Personal Trauma
For military sexual trauma and other personal trauma, this lists markers VA can use when there is no report of the event: behavior changes such as unexplained leave use, requests to change duty assignment, changes in performance, or clinic visits without a clear diagnosis. Companion Section B adds that post-service behavior changes can count too if they can reasonably be tied to the event.
M21-1, Part X, Subpart ii, Chapter 4, Section A
Rating Decisions for Reduction Due to Improvement
Before cutting a rating, VA needs a thorough exam adequate for rating that shows real improvement in your ability to function in ordinary life, including work. Ratings in place for five years or more get extra protection under 38 CFR 3.344, and a cut to a running award triggers the advance notice process in 38 CFR 3.105(e).
M21-1, Part X, Subpart ii, Chapter 5, Section A
Revision Due to Clear and Unmistakable Error (CUE)
Defines CUE in three parts: the correct facts weren't before the decision maker or the law was applied wrong, the error would have clearly changed the outcome, and it's judged on the record and law at the time. The manual calls CUE undebatable, so if a different outcome isn't absolutely clear, it isn't CUE.
M21-1, Part II, Subpart iii, Chapter 2, Section B
Supplemental Claims
Defines a Supplemental Claim and what VA expects with one: the prescribed form and potentially new evidence. It also covers how VA handles an incomplete Supplemental Claim. Note that Higher-Level Review procedures do not appear in the M21-1 table of contents; VA's public HLR page is at va.gov/decision-reviews/higher-level-review/.
This is general education, not legal advice, and not from the VA. Laws and regulations change, so always check the official source linked on each entry. For advice on your own claim, work with a free VA-accredited representative or a Veterans Service Organization. We are not the VA and are not affiliated with the VA.