A VA DBQ (Disability Benefits Questionnaire) is a standardized form used to capture the medical details VA needs to evaluate disability claims. VA explains that DBQs help collect necessary medical information to process disability claims, and that you can use DBQs to submit medical evidence from your health care provider.
VA also explains that DBQs are part of the C&P exam workflow—examiners may ask questions from the DBQ for the condition you're claiming. VA does not pay or reimburse costs for completing or submitting DBQs.
VA regulations state that when medical evidence with a claim is not adequate for rating purposes, VA will authorize an examination, and people scheduled for exams are required to report.
The same regulation allows VA to accept private or government hospital/exam reports—or a private physician statement—if otherwise adequate for rating purposes. VA's claim exam page also explains that not everyone needs a claim exam; if there is enough medical evidence, VA may use the Acceptable Clinical Evidence (ACE) process instead of an exam.