The mission of the Office of the County Auditor (OCA) is to provide independent and objective assurance and consulting services designed to add value and improve the County’s operations while promoting transparency and accountability in government. The OCA assists the County in accomplishing its objectives by bringing a systematic, disciplined approach to evaluate and improve the effectiveness of countywide risk management, control, and governance processes.


The OCA operates in accordance with the County Ordinance, Chapter 2, Article IV, Division 6, Auditor, Sec. 2-311, which grants the OCA the authority to conduct financial, management and performance audits of all Cook County departments, offices, boards, activities, agencies and programs and in any government entity that is funded in whole or in part by the County pursuant to the County’s annual appropriation bill.


An internal audit department plays a significant role in the development and sustainability of a strong internal control system. The internal audit activity provides assurance to management and the audit committee that risks to the organization are understood and managed appropriately. The following are the major roles and responsibilities of the internal audit function.

  • Assess risk Countywide to identify the audit universe and apply audit resources in the most effective and efficient manner
  • Conduct value added audits in a professional manner with high integrity
  • Evaluate and provide reasonable assurance that risk management, control, and governance systems are functioning as intended and will enable the organization’s objectives and goals to be met
  • Report noncompliance issues and internal control deficiencies directly to the President, Board of Commissioners and Audit Committee and provide recommendations for improving the organization’s operations, in terms of both efficient and effective performance
  • Assess the information technology environment and associated risk exposures
  • Maintain open communication with the Board, Cook County leadership, and Audit Committee
  • Team with other internal and external resources as appropriate
  • Adhere to auditing standards
  • Comply with continuous education and staff development requirements
Location Title
Main Office
Location Phone
Location Hours
Sunday: Closed
Monday: 8:00 am-4:00 pm
Tuesday: 8:00 am-4:00 pm
Wednesday: 8:00 am-4:00 pm
Thursday: 8:00 am-4:00 pm
Friday: 8:00 am-4:00 pm
Saturday: Closed

Agency Head

Mary Modelski, County Auditor