As a result of gradual shifts in the market for audit services, we expect financially stressed public companies to be increasingly audited by regional firms, who, in turn, will be increasingly likely to issue going concern reports to their financially stressed public companies. Our expectations challenge the view that larger audit firms, in order to avoid exposure to litigation, report more conservatively. To address these issues, we examine the 22 years between 1989 and 2010, which we classify into four ERAs  We initially document that over time, financially stressed public companies are shifting to regional audit firms, partly due to the actions of larger audit firms shedding these clients, which represent ex-ante conservatism. In contrast, audit firm reporting represents ex-post conservatism. We next show that over time, for their financially stressed public clients, regional audit firms are increasingly more likely to issue going concern reports, and BigN audit firms are increasingly less likely to issue going concern reports. We also show that in more recent ERAs, regional audit firms have been more likely than BigN and national audit firms to issue a going concern report to their financially stressed pubic clients. Overall, our evidence suggests that more recently, larger audit firms, relative to regional audit firms, acted more proactively to lessen their litigation risks through increasing centralization of client selection and acceptance processes. However our evidence suggests that more recently, to lessen their litigation risks, regional audit firms, relative to BigN and national audit firms, acted more conservatively by issuingmore going concern reports to their financially stressed public clients