(CNN) Denise Bierly was looking forward to the next phase of her life. At 52, and with two grown sons, the single mother's mind was turning to travel, book clubs and saving for retirement.

Then she got the phone call.

A 6-year-old girl needed a permanent home, the adoption case worker said. Already the child had bounced between 10 foster homes after being removed from her original home because of abuse. She deserved a better life and a strong parent, and Bierly -- who later fell for the child -- was the sort who could give her both.

She's been steeped in the adoption world for 27 years. Her oldest son is adopted, and she's a family attorney who also serves as director of adoption for the Academy of Adoption and Assisted Reproduction Attorneys . She understood what was at stake.

She began thinking about what a young child would mean for her finances. Facing an unexpected new round of summer camps, school expenses, extracurricular activities and future college tuition bills, she took comfort knowing she would qualify for the full amount of the one-time adoption tax credit, or $13,570 per child.

"I don't know what I would have done without the credit," said Bierly, of State College, Pennsylvania. "It was in the calculation for me, as a middle-class person practicing law," and it shaped her decision to meet with the adoption team.

Bierly will finalize the adoption of her first daughter on December 22. If the new GOP tax bill goes into effect as it reads right now, she may be getting that needed credit just under the wire.

Defining 'pro-family'

House Republicans unveiled a 429-page tax overhaul last week, and among the proposals in the " Tax Cuts and Jobs Act " is getting rid of the adoption tax credit which has been on the books for 20 years.

This means, if this bill were to pass this year as is, families that finalize adoptions starting in 2018 wouldn't have access to the credit.

The amount of the credit, as it stands right now, starts to phase out when families have an adjusted gross income above $203,540 and is off limits once that income exceeds $243,540. Adoption advocates say the credit exists for families who may not be able to afford adoption otherwise.

The main architect behind the new tax bill, Rep. Kevin Brady, is the father of two adopted children himself. But the chairman of the Ways and Means Committee never used the adoption tax credit, a committee spokeswoman confirmed.

Brady, a Republican from Texas, argues that the tax credit leaves families behind, especially those that don't itemize or face big tax bills. Instead, he and other bill proponents point to how the reform would nearly double the standard deduction individuals and families can take. It also creates the Family Credit, which includes a new $300 credit for each for parent and non-child dependents, and expands the child tax credit from the current $1,000 to $1,600.

"I'm convinced that if we give tax relief to families every year -- they can use their paychecks for what matters most to them -- including adopting children," he said in a written statement to CNN. "We are working to give families not only help when they're adopting but every year when that child is growing up, by making sure they have more in their paychecks to raise kids."

Bierly and others in her network say the loss of the credit will mean lost adoptions. In 2015, nearly 64,000 families used the credit to some degree. And for a bill that touts itself as being "pro-family," they believe the proposed cut amounts to hypocrisy.

"There are children who have no families. What's more important than that?" said Mary Boo, executive director of the North American Council on Adoptable Children . "We've talked to thousands of families who could not have adopted without that credit. We know it's important."

The cost for adoptions vary, but each year Adoptive Families , a magazine and online resource, conducts a survey to take the pulse of what people are spending. The latest survey , looking at adoptions finalized in 2015 and 2016, showed domestic newborn adoptions cost an average of $37,000 and international adoptions averaged about $42,000. Adoptions from the U.S. foster care system cost little in comparison, on average about $2,600, assuming there are no complications. And that doesn't mean parents won't incur plenty of expenses, especially when the children have special needs -- including, for example, those born with addictions.

"Financial incentives do make a difference in people's decisions on whether to adopt," said Adam Pertman, president and founder of the National Center on Adoption and Permanency . "Not that they do it for the money, but it's expensive and it makes a difference and helps people get to yes."

Bigger than politics

When talk of repealing the credit started percolating, a coalition of activists geared up to respond. They launched a movement -- " Save the Adoption Tax Credit " -- hoping to stamp out any further discussions.

One of the people involved in this working group is Michaela Sims, a Washington, D.C., lobbyist and former senate staffer. She's known her way around Capitol Hill for 20 years and isn't easily rattled.

"Nothing fazes me anymore, and I've been specifically preparing for this [proposed cut] for over a year," said Sims, 47. "But when I saw it in black and white, it took my breath way."

Michaela Sims Stewart, who goes by her maiden name professionally, thanks the adoption tax credit for allowing her and her husband Jon to bring Sam, left, and Jack into their family.

A mother of two adopted boys, now 9 and 11, she and her husband know firsthand the importance of the tax credit. Between her husband's work as a special education teaching assistant and her work on the Hill when they adopted, those tax credits made all the difference.

The issue, she points out, is bipartisan and bigger than politics. Even some of the most conservative voices out there are weighing in with their outrage.

The United States Conference of Catholic Bishops issued a statement Monday, calling the credit "life-affirming assistance" and "vital as a pro-life concern."

The president of Focus on the Family, Jim Daly, also entered the mix.

"More than 60 percent of adopted children in the U.S. are adopted by middle- and lower-income taxpayers," he wrote in a blog post last week. "Almost one-half of children adopted from foster care live in families with household incomes under $75,000. ... Eliminating [the tax credit] is unacceptable. We can do better as a nation."

Lost adoptions hurt more than children and the families who want them; society also pays a price, Daly and other advocates say.

Children in foster care who age out of the system, meaning they reach 18 without being adopted, are less likely to be positive contributors, according to numbers culled by the National Council for Adoption . Only 6% graduate from college, 25% don't get a high school degree or GED and only 48% are employed. Half have substance abuse problems, 40% spend time homeless, and of the young men who age out, 60% have been convicted of a crime.

Furthermore, every child that's adopted saves the government $127,000 in long-term foster care costs, says Schylar Baber, executive director of Voice for Adoption , which works on behalf of the 112,000 children awaiting adoption in the foster care system.

The issue of a family getting a tax credit, however, "is much broader than dollars and cents," he said. "It's about a child and the life of a child."

'Chasing a carrot'

Kendra and Mike Taylor, who live outside Nashville, have spent years determined to give children a chance.

They married nine years ago and, as devout Mormons, have always believed having a family was part of Heavenly Father's plan. For years, they've tried to have children to no avail. They've grappled with the pain of not walking the path they imagined and found comfort in their faith. God has something else in mind for them: adoption.

Kendra and Mike Taylor are hoping to adopt siblings from foster care.

For a year and a half, they've been on a journey to adopt siblings from foster care. They've seen on the adoption websites how siblings separate, how the oldest children often get left behind, and their hearts couldn't take it.

"We decided to go with harder-to-adopt kids and to give them the love and stability that everyone deserves," said Kendra, 30, a part-time gymnastics coach. "Just because they've had a rough start doesn't mean it has to be that way for the rest of their lives."

They've been preparing themselves to "bring in three or four kids at once," said Mike, 32, a branch manager for a pest control company. "If you have that ability, it feels like a moral obligation."

The home study process is complete. They've filled out piles of paperwork, undergone physicals and collected recommendations. They've participated in special trainings, over the course of weeks, to help them deal with the sorts of traumas often experienced by foster children. And they've spent about $8,000 already, between the private company they hired to do their home study, the inspections they had done of their home and the trainings. Finally they are in the phase where they can look for a match.

Then this new tax bill came along to potentially derail their efforts. Even if they found their match tomorrow, it would take six months to finalize the adoptions. The legal fees that await them could vary, depending on the state where the siblings live, how many children are in the group and whether or not parental rights are severed. The Taylors estimate they could face charges of anywhere from $4,000 to $12,000 per child. If the tax credit incentive disappears before they finalize anything, it would put their plans to have a family on hold.

"If you have a child naturally and in the hospital, you have health insurance to cover the bills," Kendra said. "Nothing covers the legal fees for adoption. You're on the hook for it."

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The adoption tax credit has offered some solace. The idea of waiting years to save up or having to take a second mortgage out on their home so they can have a family leaves them frustrated.

"We had a plan, we're halfway through it, and our path got redirected without our consent," Mike said. "It's like we're chasing a carrot that's been pushed out further."