First claim. Start with a VSO or file with a claims agent who will wait for the decision to bill. Evidence quality at filing matters more than who submits it. Check the VA rating for PTSD criteria if mental health is part of your claim.
Denied or low rating. A paid advocate earns the most here, because back pay has accumulated and the review lane you pick decides how fast you are paid. See VA appeals attorney for the lanes and accredited VA claims agent if you prefer an agent.
Cannot work. Pick someone with TDIU experience. Start at TDIU lawyer, and add SSDI lawyers for veterans if you may also qualify for Social Security.
Comparing firms. Use the criteria on best VA disability attorneys: accreditation, fee terms in writing, who actually works the file and how they communicate.
Before you sign anything, confirm the name in the VA accreditation search, ask who handles the file day to day, and ask what happens to the fee if you win less than expected. A good advocate answers all three without hedging.