About 5 years ago, I left my job, after being there only a year. I had a retirement plan at work that apparently had a 3 year vesting period. I did not know that. Apparently the employer did not notify me of this and I have been getting statements in my 403(b) retirement account showing that this was my money. Therefore I thought these were indeed my monies and I have relied upon this for my retirement. Five years later they now want to take these funds back. Does you know if my employers failure to remove these funds from my account when I left employment, or their failure to notify me that these funds were no longer mine, give me any rights to claim these funds as my own?
You'd probably have to sue them to get the money. In most cases those statements have disclaimers all over them telling you about the vesting period and technically that extra money was probably never really in your account. Normally the statements also break out the actual contributions from the employer match part and have a footnote about the vesting policy. Unless the employer was completely incompetent in their management of this account, I am betting they will have documentation of the policy that you supposedly were given.
You probably have very slim chances of prevailing on this unless they were very lax in their documentation.
I'd say re-check the statements and your employee manually carefully for any mention of vesting. If you don't find it, ask the employer (nicely) where you were notified of this. If they still can't produce any documentation, then sue them.
If the contributions were yours, they are vested immediately. Otherwise, there are some rules laid out on the Department of Labor website: