Deferred compensation plans tend to offer better investment options than most 401(k) plans, but are at a disadvantage regarding liquidity. Nassau County employees can access their 457b retirement accounts to check balances, view their retirement plan activity and more.A voluntary retirement savings plan that provides quality investment options, investment educational programs and related services. 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. You will need your Social Security Number and PIN to enroll in the Plan online. 403(b) PLAN AND 457(b) DEFERRED COMPENSATION PLAN. Nassau Simple Annuity is a multi-year guaranteed annuity that offers you protection from market volatility, a choice of 4 or 6 year guarantee periods. Do not enter contributions to a section 401(k) deferred arrangement, section 403(b) annuity, or section 457 deferred compensation plan.