What you really want to be asking if you can roll money over from a 457(b) to a Roth IRA. The answer to that is Yes, you can roll over any amount you want as often as you want, 457(b) plan permitting, but these rollovers will generally be taxable unless the rollover is from a designated Roth account in the 457(b). The long-term benefit of paying the taxes on the rollover will be that growth in the Roth IRA will be tax-free compared to taxable growth in the traditional 457(b) account if the funds remain there.
