Participants of the program select a designated monthly amount to deduct from their paychecks and then select investment options. Taxdeferred 457 retirement plan contributions can be used to purchase eligible service credit.We are pleased to offer the 403(b) Tax Sheltered Annuity Plan and the 457(b) Deferred Compensation Plan to eligible employees. How do I set up RMDs? Employees make pre-tax contributions deducted from salary, which lowers taxable income. Contra Costa County (the "County'') maintains this Contra Costa County Deferred. Deferred Compensation 457b Plan. If the Plan is tax deferred, do I ever pay taxes?