The window to begin receiving benefits at discharge is 180-90 days prior to your retirement/separation date. I personally recommend having the paperwork already completed and ready to handover to the VSO at the 180 day mark. Make sure you keep track of your paperwork’s progress thru the system.
I unfortunately had a VSO, that retired immediately after submitting my paperwork, and they didn’t get a replacement for 4 months. The original VSO submitted my documents but the “receiving office” in Wisconsin failed to upload my medical records so they rejected my claim for lack of paperwork. I spent the next 70 days trying to get a status update, which couldn’t do because I didn’t have a local VSO to work with.
So the end result was the VA, rejected my BDD claim and stated they wouldn’t BEGIN processing my claim until my DOS versus the 180-90 days prior.
This started in Dec 2019, Mar 2020 is when I finally got some answers, which was too late at that point.
Fortunately, I was hired by an Air Line, got in class, got sent home from training, withdrew retirement, and now I’m back on AD.
At least I get a do-over when it comes to filing a disability claim, and I’m a lot more knowledgeable on the process now.