U.S. lawmakers are considering changes to the tax deductibility of charitable contributions, scrutinizing a benefit that is expected to allow 38.7 million households to claim a deduction for 2012.

Possible changes would include imposing a dollar cap on all itemized deductions, limiting the tax rate at which contributions can be deducted and replacing the deduction with a credit.

“We want to ensure that whichever policies we ultimately decide to pursue are crafted in a way that makes the tax code simpler, fairer and easier to comply with,” said Representative Dave Camp, chairman of the House Ways and Means Committee, which is holding a hearing today on the subject. “We want to hear from this community before considering proposals.”

The 96-year-old deduction has come under scrutiny as lawmakers in both parties look for ways to broaden the tax base, either to lower rates or reduce the budget deficit. President Barack Obama has proposed limiting the deduction’s benefit for those in the top three tax brackets.

Critics of the charitable tax break note that it benefits only the one-third of taxpayers who itemize their deductions, particularly those with the highest incomes who can donate the most.

Camp, a Michigan Republican, wants his committee this year to approve a rewrite of the U.S. tax code that would lower rates and curb some tax breaks.

Nonprofit executives from across the country are testifying at the hearing, maintaining that the deduction differs from other breaks and noting the work their groups do to reduce poverty. They warned that limits on the deduction would reduce giving.

“The charitable deduction and its encouragement of charitable giving is hardly a loophole or a benefit for the rich,” said Kevin Murphy, president of the Berks County Community Foundation in Reading, Pennsylvania, and chairman of the board of directors of the Council on Foundations Inc. in Arlington, Virginia.

“We cannot allow ourselves to lose sight of the fact that the person who benefits from those charitable gifts isn’t the donor,” Murphy said. “It’s those hungry children.”