The probability of getting audited is much lower today than it was 30 years ago, but is up since the year 2000. It is definitely income dependent.
If you made more than $200,000, you had a 3.26 % probability of being audited in 2013, but a less than 1% probability if you made less than that. Over $1mm in income? You’ve got a 1 in 10 chance.