The Senate approved President Joe Biden's $789 billion health, climate and tax bill, which includes $80 billion to hire 87,000 IRS workers.
Republican lawmakers who opposed the bill say it will target small business owners, people who work from home, rideshare drivers, TikTokers and YouTubers.
87,000 IRS workers will be put to work auditing 1.7 million middle class, according to Republicans.
"The reality is a significant portion raised from their IRS funding bloat would come from taxpayers with income below $400,000," said Republican Sen. Mike Crapo of Idaho.
IRS Commissioner Charles Rettig disagreed, saying the $80 billion in funding would not increase audits of households making less than $400,000 per year.
IRS audits have dropped over the past decade, according to the Biden administration. That's a loss of $207 billion in income tax revenue.
The Biden administration is particularly annoyed that influencers are earning millions of dollars recording TikTok videos and not paying their fair share of taxes.
The IRS will also go after anyone who receives money through so-called digital payments networks such as Zelle and CashApp.
Those who have been audited say it is a painful experience. The burden is on the taxpayer to prove they earned less than what the IRS says they earned.
If an Uber driver exaggerated his mileage on his tax form he will need receipts to prove it. Republicans say if gig workers can't prove their mileage or car expenses, they will owe a lot of money to the IRS.
IRS workers will also investigate anyone who applied for PPP loans using false information.