This study examines changes in a company’s audit committee accounting expertise following an M&A transaction. M&A accounting (ASC 805) is complex, nuanced, and error-prone. An M&A also involves significant operational and financial changes for the acquirer, including changes in internal control over financial reporting. Thus, an acquirer’s demand for accounting expertise is likely heightened at the time of an M&A. This study provides the first insights (to my knowledge) regarding the role of accounting experts in the dynamic M&A setting. In a sample of relatively large (on average) M&As, I document that there are financial reporting benefits (reduced likelihood of restatements, higher likelihood of timely goodwill impairments, and smaller allocations of purchase price to in-process research and development) associated with changes/increases in audit committee accounting expertise. Further, my results suggest that changes/increases in audit committee accounting expertise matter more than changes/increases in other types of audit committee expertise (supervisory, industry, and M&A contextual). I document that changes/increases in audit committee accounting expertise are positively associated with accounting and business complexities. Collectively, the evidence suggests that accounting expertise is valuable in the M&A setting. This provides support for the SEC’s definition (in its 2002 proposal, although not in its final 2003 rule) of audit committee financial experts as those with accounting-specific backgrounds (SEC 2002, 2003). / Business Administration/Accounting