The VA has a duty to assist you, but you have duties too. Miss them and you can sink your own claim.
The VA has a legal duty to assist you in developing your claim. But that duty is a two-way street, and I have watched strong claims collapse because the veteran dropped their end.
Show up to your C&P exam
Missing a scheduled examination without good cause can get your claim decided on the existing record, or denied outright. If you cannot make it, reschedule; do not simply skip it.
Provide what only you can provide
The VA will request federal records, but private treatment records, buddy statements, and your own account of symptoms are yours to supply. When the VA asks, respond inside the deadline.
Keep your contact information current
Decisions, exam notices, and evidence requests go to the address on file. A missed letter can mean a missed deadline. Keep your mailing address, phone, and representative information up to date so nothing important lands in a dead mailbox.
Every VA disability claim is adjudicated under the procedures in M21-1, the VA's internal Adjudication Procedures Manual, and the regulatory standards in 38 CFR Parts 3 and 4. Raters are bound by these rules, and when they deviate, veterans have grounds to challenge the decision. Under Gilbert v. Derwinski, the benefit-of-the-doubt standard at §3.102 requires the VA to resolve every evidentiary tie in the veteran's favor. Under Esteban v. Brown, separate disabilities producing separate functional losses must be rated independently, even when they arise from the same injury, the VA cannot collapse distinct impairments into one rating.