Fiscal year (FY) 1986 results of the annual unit cost study of the public community colleges in Illinois are presented, including basic data on course offerings, enrollments, and costs. After an introductory overview, data and analyses are provided, covering FY 1986 net instructional costs compared with previous years; net and full instructional unit costs and total institutional unit costs; FY 1986 net instructional unit cost by cost categories; indirect instructional support unit cost; new instructional unit cost in seven instructional categories; net instructional unit cost by subject area; and unit cost comparative analysis. Highlighted findings include the following: (1) the state average net instructional unit cost increased from $84.87 in FY 1985 to $92.03 in FY 1986; (2) in FY 1986, net instructional cost per full-time equivalent (FTE) student was $2,761, full instruction cost was $2,882, and total institutional cost was $3,091; and (3) public service costs, which represent the cost of non-credit community education and community service activities provided by the colleges to governmental agencies, business and industry, and the community itself, rose to $39,329,025, representing a 23% increase from FY 1985. Total expenditures reports are appended. (EJV)