About the Green Book
United States Government Accountability Office (GAO)
GAO Purpose[1]
GAO, often called the "congressional watchdog,” is an independent, non-partisan agency that works for Congress. GAO examines how taxpayer dollars are spent and provides Congress and federal agencies with objective, non-partisan, fact-based information to help the government save money and work more efficiently.
GAO History[2]
The Budget and Accounting Act created GAO in 1921 when Congress realized the need to control growing government expenditures and debt after World War I. Until the end of World War II, GAO primarily checked the legality and adequacy of government expenditures.
After World War II, as government responsibilities and programs grew, so did GAO. The focus of our work shifted toward helping Congress monitor executive branch agencies’ programs and spending.
In 1974, Congress broadened GAO's evaluation role and gave us greater responsibility in the budget process. This was when we started to recruit scientists, actuaries, and experts in fields such as health care, public policy, and computers.
In 1986, we assembled a team of professional investigators, many with law enforcement backgrounds, to look into allegations of possible criminal and civil misconduct.
During the last 20 years, we’ve strived to improve accountability by alerting policymakers and the public to emerging problems throughout government.
In 2004, GAO's legal name changed from the General Accounting Office to the Government Accountability Office. The change reflected the agency’s expanding role in a growing federal government. Moving beyond financial audits, GAO began conducting performance audits—examining how government programs were performing and whether they were meeting their objectives.
In 2021, GAO celebrated a century of service as a source of objective, non-partisan information on government operations. Today, our agency that once checked millions of government vouchers has become a multidisciplinary organization equipped to handle Congress’s toughest audit and evaluation assignments.
We have looked at contemporary issues like opioid addiction, the gig economy, affordable housing, and food safety. The agency has also established a science and technology team to meet Congress’ growing need for information on cutting edge issues like artificial intelligence and infectious disease modeling. GAO also evaluated the largest response to a national emergency in U.S. history, the $2.6 trillion COVID-19 response legislation, and made recommendations about how to improve its effectiveness in dealing with public health issues and the economy.
GAO Standards for Internal Control in the Federal Government
Created as a result of the Federal Managers' Financial Integrity Act of 1982 (FMFIA).
Provides standards for establishing, maintaining, and evaluating internal control systems in government entities.
About the Green Book
The Green Book is the common name for:
Standards for Internal Control in the Federal Government (May 2025)
Published by the United States Government Accountability Office (GAO)
US GAO Green Book Documentation Requirements
Assessment Observations Compared to Green Book Components, Principles, & Attributes
Control Environment
Component: Control Environment - The foundation for an internal control system. It provides the discipline and structure to help an entity achieve its objectives.
- Principle 1 - Demonstrate Commitment to Integrity and Ethical Values
- Principle 2 - Exercise Oversight Responsibility
- Principle 3 - Establish Structure, Responsibility, and Authority
- Attributes (3.01, 3.02, 3.03, 3.04, 3.05, 3.06, 3.07, 3.08, 3.09, 3.10, 3.11, 3.12)
- Principle 4 - Demonstrate Commitment to Competence
- Attributes (4.01, 4.02, 4.03, 4.04, 4.05, 4.06, 4.07, 4.08)
- Principle 5 - Enforce Accountability
- Attributes (5.01, 5.02, 5.03, 5.04, 5.05, 5.06, 5.07, 5.08)
Risk Assessment
Component: Risk Assessment - The identification and analysis of risks facing the entity as it seeks to achieve its objectives. This assessment provides the basis for developing appropriate risk responses.
- Principle 6 - Define Objectives and Risk Tolerances
- Attributes (6.01, 6.02, 6.03, 6.04, 6.05, 6.06, 6.07, 6.08, 6.09, 6.10)
- Principle 7 - Identify, Analyze, and Respond to Risks
- Attributes (7.01, 7.02, 7.03, 7.04, 7.05, 7.06, 7.07, 7.08, 7.09, 7.10, 7.11, 7.12, 7.13, 7.14, 7.15)
- Principle 8 - Assess Fraud, Improper Payment, and Information
- Attributes (8.01, 8.02, 8.03, 8.04, 8.05, 8.06, 8.07, 8.08, 8.09, 8.10, 8.11, 8.12, 8.13, 8.14, 8.15, 8.16, 8.17, 8.18, 8.19, 8.20)
- Principle 9 - Identify, Analyze, and Respond to Change
- Attributes (9.01, 9.02, 9.03, 9.04, 9.05, 9.06, 9.07, 9.08, 9.09, 9.10, 9.11, 9.12, 9.13)
Control Activities
Component: Control Activities - The actions management establishes through policies and procedures to mitigate risks to achieving the entity's objectives to acceptable levels.
- Principle 10 - Design Control Activities
- Attributes (10.01, 10.02, 10.03, 10.04, 10.05, 10.06, 10.07, 10.08, 10.09, 10.10, 10.11, 10.12, 10.13, 10.14, 10.15, 10.16, 10.17, 10.18, 10.19, 10.20, 10.21, 10.22, 10.23)
- Principle 11 - Design General Control Activities over Information
- Attributes (11.01, 11.02, 11.03, 11.04, 11.05, 11.06, 11.07, 11.08, 11.09, 11.10, 11.11, 11.12, 11.13, 11.14, 11.15, 11.16, 11.17)
- Principle 12 - Implement Control Activities
- Attributes (12.01, 12.02, 12.03, 12.04, 12.05)
Information and Communication
Component: Information and Communication - The quality information management and other personnel communicate and use to support the internal control system.
- Principle 13 - Use Quality Information
- Attributes (13.01, 13.02, 13.03, 13.04, 13.05, 13.06, 13.07)
- Principle 14 - Communicate Internally
- Attributes (14.01, 14.02, 14.03, 14.04, 14.05, 14.06, 14.07, 14.08)
- Principle 15 - Communicate Externally
- Attributes (15.01, 15.02, 15.03, 15.04, 15.05, 15.06, 15.07, 15.08, 15.09)
Monitoring
Component: Monitoring - Activities management establishes and operates to assess the quality of performance over time and promptly resolve the findings of audits and other reviews.
- Principle 16 - Perform Monitoring Activities
- Attributes (16.01, 16.02, 16.03, 16.04, 16.05, 16.06, 16.07, 16.08, 16.09, 16.10)
- Principle 17 - Evaluate Issues and Remediate Deficiencies
- Attributes (17.01, 17.02, 17.03, 17.04, 17.05, 17.06, 17.07, 17.08)
The Green Book is organized into 17 Principles covering:
- Integrity and ethical values
- Oversight responsibility
- Risk management
- Control activities
- Information and communication
- Monitoring
