We find that the audit report lag is significantly higher for former Andersen clients (that did not follow their Andersen partner to the new audit firm) than for clients voluntarily changing auditors from another Big 5 predecessor for the fiscal year ended December 31, 2002 (the first year with the new auditor for ex-Andersen clients). The differences in audit reporting lags between the two groups are not significant for fiscal years ended December 31, 2000 (the last year before Andersen's Enron related problems surfaced), or 2003 (the second year with the successor auditor). We also find that clients with voluntary (i.e., non-Andersen) auditor changes have only marginally higher audit reporting lags compared to clients without auditor changes. Our results, focusing on a cost component of involuntary auditor changes, thus provide relevant empirical evidence for debates surrounding mandatory auditor rotation. We also find that ex-Andersen clients that followed the Andersen partner to the new audit firm had shorter audit report lags than ex-Andersen clients that did not follow their Andersen partner. Our findings highlight the importance of individual relationships in the auditing process, and suggest new avenues for future research. [PUBLICATION ABSTRACT]