As the Democrats’ spending plan moves closer to a House vote, one of the more controversial provisions — nearly $80 billion in IRS funding, with $45.6 billion for “enforcement” — has raised questions about who the agency may target for audits.

IRS Commissioner Charles Rettig said these resources are “absolutely not about increasing audit scrutiny on small businesses or middle-income Americans,” in a recent letter to the Senate.

However, with the investment projected to bring in $203.7 billion in revenue from 2022 to 2031, according to the Congressional Budget Office, opponents say IRS enforcement may affect everyday Americans."Our biggest worry in this is that the burden for these audits will land on Walmart shoppers,” Rep. Kevin Brady, R-Texas, said Tuesday on CNBC’s “Squawk Box.”

Overall, IRS audits plunged by 44% between fiscal years 2015 and 2019, according to a 2021 Treasury Inspector General for Tax Administration report.

While audits dropped by 75% for Americans making $1 million or more, the percentage fell by 33% for low-to-moderate income filers claiming the earned income tax credit, known as EITC, the report found.

Ken Corbin, chief taxpayer experience officer for the IRS, said returns claiming the EITC have “historically had high rates of improper payments and therefore require greater enforcement,” during a May House Oversight Subcommittee hearing.

Since many lower-income Americans are wage earners, these audits are generally less complex and many may be automated.

“The resources to modernize the IRS will be used to improve taxpayer services — from answering the phones to improving IT systems — and to crack down on high-income and corporate tax evaders who cost the American people hundreds of billions of dollars each year,” according to a Treasury official.

While the department estimated in a 2021 report that the funding may cover about 87,000 employees, the hires may include a range of positions, with the IRS sharing the exact numbers in the coming months.

“The majority of new employees will replace the standard level of staff departures over the next few years,” the Treasury official said.

How the IRS picks which tax returns to audit

Currently, the IRS uses software to rank each tax return with a numeric score, with higher scores more likely to trigger an audit. The system may flag a return when deductions or credits compared to income fall outside of acceptable ranges. 

For example, let’s say you make $150,000 and claim a $50,000 charitable deduction. You’re more likely to get audited because it’s “disproportionate” to what the system expects, explained Lawrence Levy, president and CEO of tax resolution firm Levy and Associates.