Can someone please shed some light as to how retroactive compensation is calculated? In early January I was awarded an increase in benefits and I think the regional office miscalculated my retro. The effective date of my award is July 16, 2009. My award letter says that the payment start date is August 1, 2009. According to my calculations, I should have received 18 months of compensation instead of 17. I called the 800-number and was told that “benefits are paid in arrears.” 38 USC Sec. 5111 says that payments commence on the first day of the calendar month following the effective date. Again, that would be August 1, 2009. The statute says nothing about payments being in arrears. Am I missing something? Thanks.