Two forms of expertise can influence audit quality: industry and task-specific expertise. Anecdotal evidence suggests that tax knowledge is task-specific, rather than industryspecific and audit offices with increased exposure to complex tax issues develop this taskspecific expertise. Using outcomes related to audits of the income tax accounts, we examine whether tax task-specific knowledge (TSK) affects the audit quality of the income tax accounts and find that tax TSK increases the audit quality of the income tax accounts. We also find evidence of an improved response to misstatements among audit offices with tax TSK, demonstrated by a decreased likelihood of future tax misstatements following the disclosure of a tax restatement. Finally, we observe the effect of tax TSK among audit offices with lower levels of auditor-provided tax services (APTS). This result suggests that audit offices without the benefit of knowledge spillover from APTS rely more on the tax TSK.