The credit, capped at $13,460, is aimed at helping families afford adoption, a fraught process that can drain finances along with emotions.
But those hopes were dashed when details of the GOP tax proposal were unveiled Thursday, leading to a mix of surprise and disappointment.
"If they want to promote family-friendly policies, who needs help more than a child without a family?" said Mary Boo, executive director of the North American Council on Adoptable Children.
"This will make it tougher to adopt. Period," Schylar Baber, executive director of Voice for Adoption, said.
Brady defended the decision to cut the adoption tax credit by pointing out that some families can't claim the credit because they don't pay enough in taxes or they don't itemize their tax bill.
"This credit is not working," Brady said in an interview with The Washington Post.
Brady said the overall effect of the Republican’s tax plan — which combines cuts to individual and corporate tax rates with the loss of certain tax breaks — would be "giving families more in their paychecks, especially the middle-class families that are crucial for adoption.”
He also pointed out the child tax credit would grow by $600 to $1,600 per child, aiding families whether they adopt or not.
"I think this is a better approach for the vast majority of Americans who are left behind," Brady said.
But adoption advocates said the proposed changes to the U.S. tax system would end up discouraging adoption.
"It doesn't balance out the loss and doesn't act as an incentive," said Adam Pertman, president of the National Center for Adoption and Permanency.
Jedd Medefind, president of the Christian Alliance for Orphans, said he's seen the tax credit bridge the difference between families being able to move forward with adoption and backing out. He expects that there will be fewer adoptions if the credit is eliminated.
About 120,000 children are adopted each year. Some of them are stepchildren finalizing the process. Some don't have parents. Many are taken from foster care.
The adoption tax credit is designed to help families pay for adoption fees or help them afford taking in two children to avoid splitting up siblings. It was created in 1996 and has an inflation-adjusted lifetime cap of $13,460. It's not available to families making more than $242,000 a year — that’s why, speaking at a Heritage Foundation event last year, Brady said he and his wife did not take the credit when they adopted their boys.
The credit’s cost is small compared with the tax plan's projected cost of $1.5 trillion to the debt over a decade. The government lost $355 million in revenue because of the credit in 2014, the most recent year data was available. Fewer than 74,000 taxpayers claimed the credit.
Baber, of Voice for Adoption, said the tax credit's loss would be especially hard on foster-care adoptions, where it becomes more difficult to find homes for older children.
"So, the question is, who is not going to get adopted because of this?" said Baber, who spent most of his childhood in foster care in Montana before finding a permanent home.
Adoption groups plan to push hard to save the adoption tax credit. And Brady said he is open to talking with them.
Brady might also need to talk with some House Republicans. U.S. Rep. Mark Walker (R-N.C.) said on Twitter on Friday that the adoption tax credit needs to be included in the tax bill: "Providing a home for a child that is unwanted or special needs is pro-life!"