Veterans Claim Transparency Act of 2020 This bill requires the Department of Veterans Affairs (VA) to provide an opportunity for a veteran's representative to review the veteran's disability rating determination before the rating is finalized. Under the bill, the VA must provide notice to such representative when the determination is ready to be reviewed. The period for review begins at the moment notice is submitted and ends at the earlier of (1) the moment the representative agrees with the determination, or (2) 48 hours after the notice. The VA may not finalize a determination until after the period for review has ended.