Both GAGAS and the Uniform Guidance require the auditor to communicate in writing fraud and material weaknesses and significant deficiencies in internal control to entity management and those charged with governance and to report in writing to external parties in some circumstances. This chapter describes the auditor's communication and external reporting requirements for internal control deficiencies and instances of fraud or suspected fraud. It also includes requirements for communicating and reporting waste and abuse, since they often are a result of noncompliance.