The fundamental determination whether a probate matter needs to be filed with the county court is the value of the estate of the deceased. Under Illinois law the threshold for having to file a probate case is that the gross value of the estate must equal $100,000 or more. If the estate is valued at less than $100,000 then the estate can likely be handled with the use of a small estate affidavit.
If the estate is worth $100,000 or more then a probate case must be filed. Upon the determination that the estate must be administered through a probate case, then the basic question is – did the deceased have a will? If the deceased had a will then they are deemed to have died testate, and the language of the will controls the disposition of the estate. If the deceased person died without a will, then they are deemed to have died intestate and then Illinois law pursuant to 755 ILCS 5.