Posts: 6. Sep 4 11 9:39 PM. How long is it taking the Va to pay backpay for intial claims, mine just closed on 29 Aug 11 with a rating of 60%. I'm also 22yr active duty retired on 31 August 2010 with a retro date of my claim being 1 October 2010, my CDRP begin date 1 Sep 2011 per RAS from DFAS.aiting for the VA retro pay now since April. I finally reached a competent person-I was told right now it takes 21 days after receipt of DFAS audit sheet to get payed retro- 45 days is the max right now.