U.S. lawmakers are exploring a new corporate tax break that would benefit companies already adept at avoiding taxes.

The idea—known as a patent box or innovation box—would impose a lower tax rate on income generated from patents and other intellectual property housed in the U.S. This would aid technology and pharmaceutical companies trying to maintain low tax rates that they've achieved by booking income in overseas tax havens.

The so-called innovation box also is attractive to lawmakers in both parties who are worried that companies can easily move income outside the U.S. and chase low tax rates around the world. The break could help preserve the domestic tax base threatened by tax inversions and takeovers by foreign companies, said Representative Charles Boustany, a Louisiana Republican who is working on innovation box legislation.