To win a claim for disability benefits the veteran must provide:
1) Competent evidence of a current disability
2) Medical, or sometimes lay evidence, that the injury or disease was incurred or was aggravated while the veteran was in service
3) Competent evidence that links the incurrence or aggravation of the injury or disease to the current disability.
The VA has a duty to help the veteran try to get the evidence that can prove the claim. If the veteran provides the necessary evidence, the VA then rates the severity of the disability and provides a percentage of disability based on the Schedule for Rating Disabilities. Next the VA sets the effective date for the award of compensation.