Illinois Secure Choice is a state-facilitated retirement program that makes it easy to save for retirement. Get your retirement planning on the right track.Tier 1 Regular Retirement Formula. This information applies to all active state employees. Trailhead Retirement Planning Group can help you achieve your financial goals. The SURS Traditional Pension Plan is the historical SURS Defined Benefit retirement plan. IMRF is one of the pension systems covered under the Illinois Retirement Systems Reciprocal Act allowing you combination of service credit at retirement. Each tax year, you may be required to fill out Form 5500, depending on the type of plan you choose.