Washington (CNN) House Republicans introduced their bill to repeal Obamacare's individual mandate that also aims to maintain coverage for people with pre-existing conditions and allow children to stay on their parents' plans until the age of 26.

The measure would offer individuals refundable tax credits to purchase health insurance and restructure the country's Medicaid program so that states receive a set amount of money from the federal government every year -- changes experts warn could result in millions of people losing access to insurance they received under the Affordable Care Act.

It also largely would keep Obamacare's protections of those with pre-existing conditions, but allows insurers to charge higher premiums to those who let their coverage lapse.

House Speaker Paul Ryan said Obamacare is "rapidly collapsing" and it is "time to turn the page."

"The American Health Care Act is a plan to drive down costs, encourage competition, and give every American access to quality, affordable health insurance. It protects young adults, patients with pre-existing conditions, and provides a stable transition so that no one has the rug pulled out from under them," Ryan said in a statement.

The measure sets up a political battle that could consume Congress for much of the year.

White House spokesman Sean Spicer praised the bill's release.

"Obamacare has proven to be a disaster with fewer options, inferior care, and skyrocketing costs that are crushing small business and families across America," Spicer said in a statement. "Today marks an important step toward restoring health care choices and affordability back to the American people. President Trump looks forward to working with both Chambers of Congress to repeal and replace Obamacare."

The two top Democrats on the two House committees that crafted the bill -- Reps. Frank Pallone of New Jersey and Richard Neal of Massachusetts -- railed on Republicans for writing the bill without broader input. The measure was kept in a room in a House office building last week to let members review it without risk of it leaking to the press.

Pallone and Neal invoked Trump's prior commitments, saying the proposal "would rip health care away from millions of Americans, ration care for working families and seniors, and put insurance companies back in charge of health care decisions -- contrary to everything President Trump has said he would do with his health care plan."

Conservative and moderate Republicans have raised concerns about key provisions within the bill. Conservatives say have argued that refundable tax credits are little more than a new entitlement program and some Republicans from Medicaid-expansion states have said they would not support plans that could kick millions of people off the Medicaid rolls.

Bowing to pressure from the right, House leaders instituted an income cap on the tax credit to prevent wealthier Americans from claiming it.

The House plan would also retain the so-called Cadillac tax -- which has never gone into affect -- in order to hit the budget targets required under the maneuver used to pass the bill, called budget reconciliation.

Still, Republican leaders are committed to moving forward with major tenants of the legislation and are hoping that President Donald Trump and his administration can bring wavering members on board and get the bill across the finish line.

Monday, the bill was released without any Congressional Budget Office score, a sign that Republicans may be worried about the fallout once Americans understand how many people could be affected by changes in coverage.

Strip funding for Planned Parenthood

The GOP bill also includes a provision to strip all federal funding for Planned Parenthood, which is something Republicans has vowed to do for years citing concerns over the use of taxpayer money for abortion services.

Even though current federal law bars the use of money specifically for abortions, conservatives have complained that the women's health services organization does support research they oppose. Planned Parenthood has warned that cutting off their funding will have major impact on Medicaid recipients, millions of whom obtain health care services in their clinics.

Waiting for this moment

After years of attacking Democrats for Obamacare's shortcomings and running dress rehearsals to repeal it, Republicans this week are finally facing the praise -- as well as the consequences -- of trying to revise the nation's health care system

Rep. Kevin Brady, a Republican from Texas and the House Ways and Means chairman, said in a written statement, "our legislation transfers power from Washington back to the American people. We dismantle Obamacare's damaging taxes and mandates so states can deliver quality, affordable options based on what their patient populations need, and workers and families can have the freedom and flexibility to make their own health care choices."

Two House committees have scheduled meetings on the bill for Wednesday, according to aides and committee members. Since this is the first time most lawmakers and the public will actually see the bill, it's also the most significant test to see that the legislation can at the very least survive early flogging from all sides.

The lack of a CBO score may concern lawmakers.

While Republicans had long argued their plan would give consumers more flexibility, the reality is that the GOP replacement bill was not necessarily designed to cover more people than the Affordable Care Act did. The CBO score is expected to reflect that reality, which is part of the reason it was not part of the bill's initial unveiling.

Difficult politics ahead

Schisms over how to overhaul Medicaid and how to structure refundable tax credits won't be solved anytime soon.

Republican leaders have worked aggressively to forge consensus with their members in listening sessions and meetings behind closed doors in recent weeks, but the divides between conservatives and moderates, and those between moderates and lawmakers from states that expanded Medicaid under Obamacare are not going away.

On Monday morning, Budget Director Mick Mulvaney, a former congressman with ties to House Conservatives, warned members of the Freedom Caucus about bucking their party on something as key as Obamacare repeal.

The White House hosted a "large staff meeting" Friday with administration and congressional staff to resolve outstanding issues, a senior GOP aide said. The House committees "worked over the weekend with the White House to tie up loose ends and incorporate technical guidance from the administration."

House Speaker Paul Ryan, Energy and Commerce Chairman Greg Walden, Mulvaney, HHS Secretary Tom Price, Domestic Policy Council Director Andrew Bremberg and House, among others, held a conference call Saturday to discuss the bill.

The goal in the weeks ahead will continue to be simply making enough members happy to reach 218 votes in the House and 51 in the Senate. That's the number of votes needed to pass the "repeal-plus" measure and number of people they need to convince Trump to sign it.

Republicans in the House and the Senate voted in 2015 to repeal President Barack Obama's signature legislative achievement, but members then knew they'd be protected by Obama's veto pen from suffering any of the political consequences if it went poorly.

Angry voters at town halls

This time around -- as some members have said -- the party is playing with real bullets.

Already, Democratic backlash against attempts to repeal the Affordable Care Act has been intense. Republican members across the country have returned to their districts only to be confronted by raucous crowds of constituents at town halls and outside their offices. The high-stakes negotiations have drawn such consternation that the evolving draft of the bill was being kept in an Energy and Commerce Committee office room last week, only available for Republican members of the committee to see.

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The parallels to 2009, when the Democrats started work on Obamacare, are hard to ignore. Town halls, industry participants hammering away behind the scenes to save tax breaks and carve outs, allegations that leadership is hiding the details, even some of the proposals themselves appear to more closely mirror those pursued by Democrats than most Republicans would care to admit.

This is the House GOP leadership's trust fall.

The divides are only expected to get more pronounced now that the bill has been released.

Republicans from states that expanded Medicaid under Obamacare have voiced serious concerns about rolling back a program that helped low-income people back home get health care. Non-expansion state Republicans, on the other hand, have voiced opposition to any program that allows expansion states to receive more money in the future.

"The reality of it is there is no way to get this done if you don't make whole those states that were more fiscally responsible and did not expand," Sen. Tim Scott, a Republican from South Carolina, a state that didn't expand Medicaid, told reporters last week.

This story is breaking and will be updated