Vandersloot is the CEO of Idaho Falls-based health care company Melaleuca Inc. and among donors who have given $1 million to Republican presidential candidate Mitt Romney.
In April, Vandersloot was targeted by President Obama's campaign as one of eight Romney donors with questionable records on various issues.
Vandersloot says the timing of the audits is curious and questionable.
The IRS audit is focusing on personal tax returns from 2008-09. Labor officials will examine the status of temporary foreign workers at his cattle ranch.
An IRS spokeswoman says federal laws prohibit discussing taxpayer information. Labor officials did not immediately respond Wednesday.