Department Charter


Internal auditing is an independent, objective assurance and consulting activity designed to add value and improve the operation of Maricopa County Government (County). It helps the County accomplish its objectives by bringing a systematic, disciplined approach to evaluate and improve the effectiveness of risk management, control, and governance processes.

Assurance services involve the objective assessment of evidence to provide an independent opinion or conclusions regarding an entity, operation, function, process, or system.

Consulting services are advisory in nature, and are generally performed at the specific request of an engagement client. The nature and scope of the consulting engagement are subject to agreement with the engagement client.


The Maricopa County Internal Audit Department (Internal Audit) is established by the Maricopa County Board of Supervisors (Board) by the powers granted to the Board in A.R.S. § 11-251. Internal Audit's responsibilities are defined by the Board as part of its oversight role.


Internal Audit will be governed by adherence to The Institute of Internal Auditors' mandatory guidance including the Core Principles, the Definition of Internal Auditing, the Code of Ethics, and the International Standards for the Professional Practice of Internal Auditing. This guidance sets forth required, fundamental principles for the professional practice of internal auditing and for evaluating the effectiveness of Internal Audit's performance.


Internal Audit, with strict accountability for confidentiality and safeguarding records and information, is authorized full, free, and unrestricted access to any and all of the County's records, physical properties, and personnel pertinent to carrying out any engagement. By law, Internal Audit's working papers and audit files are confidential (A.R.S. § 11-251(10)). All employees are requested to assist Internal Audit in fulfilling its roles and responsibilities. Internal Audit will also have free and unrestricted access to the Board.


The Internal Audit Director (Director) will report functionally and administratively to the Board. The Director will communicate and interact directly with the Board. The Board will approve:
  1. The Internal Audit charter
  2. The risk-based Internal Audit plan
  3. The Internal Audit budget
  4. Decisions regarding the appointment and removal of the Director
  5. The remuneration of the Director

Independence & Objectivity

Internal Audit will remain free from interference by any element in the County, including matters of audit selection, scope, procedures, frequency, timing, or report content to permit maintenance of a necessary independent and objective mental attitude.

Internal auditors will have no direct operational responsibility or authority over any of the activities audited. Accordingly, they will not implement internal controls, develop procedures, install systems, prepare records, or engage in any other activity that may impair their judgment.

Internal auditors will exhibit the highest level of professional objectivity in gathering, evaluating, and communicating information about the activity or process being examined. Internal auditors will make a balanced assessment of all the relevant circumstances and not be unduly influenced by their own interests or by others in forming judgments.

The Director will confirm to the Board, at least annually, the organizational independence of Internal Audit.


The scope of Internal Audit encompasses, but is not limited to, the examination and evaluation of the adequacy and effectiveness of the County's governance, risk management, and internal controls, as well as the quality of performance in carrying out assigned responsibilities to achieve the County's stated goals and objectives.

Internal Audit Plan

At least annually, the Director will submit to the Board an audit plan for review and approval. The Internal Audit plan will be developed based on a prioritization of the audit universe using a risk-based methodology, including input of senior management and the Board.

Reporting & Monitoring

A written report will be prepared and issued by the Director or designee following the conclusion of each Internal Audit engagement and will be distributed to the Board and others as appropriate. The Internal Audit report may include a response and corrective action taken or to be taken in regard to the specific findings and recommendations. Internal Audit will be responsible for appropriate follow-up on engagement findings and recommendations.

Quality Assurance & Improvement Program

Internal Audit will maintain a quality assurance and improvement program that covers all aspects of the County's internal audit activity. The Director will communicate to the Board on Internal Audit's quality assurance and improvement program, including results of ongoing internal assessments conducted at least annually and external assessments conducted at least every five years.

Adopted by the Board of Supervisors - June 11, 1997
Last Amended - February 17, 2016