If you elect to resign or retire from employment, we request that you provide at least two weeks advance notice of the intended separation date. Make the steps below to fill out Retirement resignation letter online easily and quickly: Sign in to your account.Submit a signed letter of resignation to your immediate supervisor, with a copy to your Human Resources Director. How Does a Retirement Letter Differ from a Notice of Resignation? Employees become fully vested in the pension plan on their 3rd anniversary.