Nassau County employees can access their 457b retirement accounts to check balances, view their retirement plan activity and more. Sign up and manage your deferred compensation retirement account.Nassau County School District, FL. 403(b) PLAN AND 457(b) DEFERRED COMPENSATION PLAN. The 403(b) and 457(b) Plans are valuable retirement savings options. A contract that is not issued in connection with a qualified retirement plan or IRA is referred to as a. "non-qualified" annuity contract. Deferred Comp Board.