I retired in 2007, originally I had CRSC and apparently deselected it at some point. Last year I was told I had to submit an entire new package to get approved. I did this around the middle of last year and it was approved at 90%, at which time they gave me a nice back pay check. They also said that I was not currently enrolled in CRSC. I was told because I had deselected it in the past and deselected it I had to wait until open season to elect CRSC which is December. I am currently waiting for my election letter and was curious once I elect it will there be a timeline and will I receive any other backpay? The backpay obviously didn't cover last year, or the first few months of this year. Also, can you submit an addendum to last years taxes paid?