The pilot project concerns academics and other critics who worry the private lawyers and accounts who create tax shelters could draft tax rules that favor their clients, The New York Times reported Friday.
"It's not the fox guarding the henhouse; it's the fox designing the henhouse," New York University political science Professor Paul Light said.
IRS General Counsel Donald Korb defended the plan, saying the project was "not changing this process one iota."
IRS lawyers will still review any new rules before they are final, he said.
But John Graham, President George W. Bush's appointee to give private interests a greater voice in the federal rule-making process, said, "Whoever's pen the first draft comes out of has a big advantage."
IRS staff has been cut by 20 percent in the past decade, the Times said. At the same time, Congress has made the tax code vastly more complex.
The agency has said it lacked the resources to issue as much guidance as taxpayers seek.
Rosie O'Donnell unveils nearly 50-pound weight loss
Putin thinks Obama would save him if he were drowning