More than 2,800 Internal Revenue Service employees who recently had been disciplined received performance bonuses totaling more than $2.8 million between Oct. 1, 2010, and Dec. 31, 2012, a government audit found.

The misconduct ranged from failure to pay taxes to misuse of government travel cards, violation of official-conduct standards and fraud, according to the report by the Treasury Inspector General for Tax Administration. The discipline included written reprimands, suspensions and even removal. The oversight agency said...