I actually had a friend who had theirs changed from a 4c to a 3b. As far as I remember it took about 9 months to have it changed. He too was awarded a VAC lump sum award. He currently as well is on the income supplement program through VAC. He did however have difficulty at first because VAC wanted him to apply for SISIP and use their benefits first. What the issue he ran into was that he never applied for SISIP after his 4c release because he didn't think he was intitled to it. VAC said before they would put him on the income supplement program he had to exist all avenues of income first, meaning he had to apply to SISIP and use any monetary benefits that he would qualify for. I know that this process has taken him months, and still isn't fully finished, the result of this was that SISIP is paying him the 2 years of LTD at 75% of his release salary, even though it is past the required time line to apply for the benefits. He was also told that they would be paying him in a lump sum for all previous months, and then at this point he would only have about 6 months of payments left of the 24 months. Once that 6 months is up, he then would be eligible to go on the income supplement program through VAC. Until he receives payment through SISIP VAC is continuing to pay him on the supplement program, but he had to sign a promise to repay note to VAC that states all monies that was paid under the income supplement program during the time frame that he was to be on SISIP will be returned to VAC once he has receives the lump sum payment from SISIP which is equal to about 18 months worth. Once he is done on the SISP LTD program ( About 6 months) he then will resubmit his application for the VAC income supplement program and will not be penalized for the money that he had received previously from the VAC income supplement program.