This paper investigates the spread of aggressive corporate tax reporting by modeling a firm's decision to adopt the corporate-owned life insurance (COLI) shelter. I use a sample of known COLI participants to examine whether certain firm characteristics are associated with the decision to adopt a COLI shelter. I find some evidence that firms with higher performance-matched discretionary accruals are more likely to adopt a COLI shelter, suggesting a positive relation between aggressive financial reporting and aggressive tax reporting. I also find that firms with greater capital market visibility are less likely to adopt a COLI shelter, consistent with a potential reputational cost for being associated with aggressive tax avoidance activities. Further, my results suggest that COLI adopters are generally R&D intensive firms with low leverage and few foreign operations. In addition to firm specific characteristics, I consider two explanations for the spread of COLI adoption motivated by theory on diffusion of innovations and institutional isomorphism. I investigate whether firms imitate prior COLI adopters and whether COLI adoption spreads through common auditors. My results are not consistent with an imitation explanation. Further, my results suggest that having the same auditor as a prior COLI adopter does not increase the likelihood that a firm will adopt COLI.