Optimum Insurance Company of Illinois, a domestic property and casualty insurance company, was placed into conservation by court order on December 28, 1984. Optimum was an affiliate of Ideal Mutual Insurance Company, an insurance corporation domiciled in the State of New York. Ideal Mutual Insurance Company was placed in rehabilitation by court order entered in the State of New York on December 26, 1984, and into liquidation by court order entered on February 7, 1985.

The company commenced business in 1980, and was licensed in Illinois only. Optimum specialized in workers' compensation coverages, as well as a small amount of general liability and full coverage automobile risks.

On January 3, 1985, Optimum was placed in rehabilitation by court order. Following unsuccessful efforts to rehabilitate the company, the Circuit Court of Cook County, Illinois, issued a final Agreed Order of Liquidation with a Finding of Insolvency on May 5, 1986.

The final date for filing proof of claim forms with the Liquidator was May 4, 1987, with the requirement that contingent claims be liquidated by December 29, 1989.  A total of 12,525 proof of claim forms were mailed to potential claimants. To date, 3,979 have been filed with the Liquidator. Early Access distributions of $5,223,757, as of January 24, 2003, have been made to the Illinois Guaranty Fund for administrative expenses.

The Liquidator recovered $3 million for Optimum creditors from Optimum's former directors and officers as a result of bringing claims for mismanagement and breach of fiduciary duty.

Class A was paid at 100%, in the amount of $5,227,296. Class D was paid at 7.4384%, in the amount of $1,548,740. The estate was closed on November 19, 2003.