To provide a fuller picture of compliance with ASC 350-20, we hand-collect data to track 893 large acquisitions across time. Our model, which links impairments to post-acquisition accounting and market performance declines as well as acquisition-year attributes, identifies 349 acquisitions as likely to impair. We provide evidence that 65 percent of these at-risk acquisitions impair in the next two years. Our study should be useful to future research as it clarifies the role of hand-collection, market to book ratios, segment-level data, and volatility. We also offer descriptive evidence on impairment patterns. Overall, we find high levels of compliance and little opportunism.