In 1984, Rotunda formed a successful duo with Barry Windham. Together, as the popular U.S. Express, they captured the Tag Team Championship twice and they took part in the first Wrestlemania. With his amateur wrestling background, Rotunda was the technician of the team while Windham was the powerhouse.
The following year, Windham left the WWF and Rotunda had a forgettable run in singles. He also teamed up with Danny Spivey in a new version of the U.S. Express, but they became jobbers. Rotunda eventually left the company to join up with his former partner in the Florida NWA territory.
After four years with NWA, Rotunda made a memorable return with the WWF, as the infamous taxman known as IRS. In no time, he became a serious contender for the Intercontinental Championship and he had a great rivalry with Bret Hart over the title.
With his brand new gimmick, he became one of the most hated heels ever and he truly started to display his great in-ring talent with his signature multiple suplex variations and his work on opponents specific body parts. Every time he found an opening, he worked on a specific body part for the whole match.
His career reached its peak when he teamed up with Ted DiBiase and formed the duo known as Money Inc. Both men formed a very successful tag team and they won the gold three times to dominate the division for almost one year.
After The Million Dollar Man retired from active wrestling, he formed a stable in which IRS was an important member. When he was associated with the Million Dollar Corporation, Rotunda mostly feuded in singles. However, he and the stable itself never achieved huge success.
IRS' last big feud with the WWF was against the legendary Undertaker. The Taxman was obviously on the losing end, but, with his amazing technical skills, he gave hard times to The Deadman.
Mike Rotunda never really reached main event status, but for five years he was an important draw in the mid-card division. No one likes taxmen and, because of that, he portrayed one of the most hated heels in WWE history.