The Senate this morning took another step toward passing a $871 billion health care bill with a vote to cut off debate and pass a 383-page amendment. But the battle is far from over.
After senators pass the health care legislation, it will have to be reconciled with the House bill in the conference committee. Both chambers have to approve the exact same bill, with a simple majority, before sending it to the president.
Democrats say the final health care bill will pass before President Obama's State of the Union address in February. But they could face a tough time resolving differences among members of their own caucus.
Even though both health care bills were crafted by Democrats and are similar in some ways, there are several significant differences between the two.
Some senators, such as Democrat Ben Nelson of Nebraska, have warned that they could yank their support for the health care bill if changes are made. For some members of the Senate, the House version of the health care bill was dead on arrival and many say that members of the House will simply have to cave in.
Meanwhile, some House Democrats, such as Rep. Bart Stupak of Michigan, who wanted strict language prohibiting federal funding for abortion, say they are unhappy with the language in the Senate bill. Stupak has refused to back down from his abortion amendment, saying he won't settle for anything less than outlined in his proposal, which would prohibit insurance firms that participate in a proposed health insurance exchange from covering abortion services.
Here is a look at some of the key similarities and differences between the House and Senate bills:
The Senate bill curbs costs by taxing so-called "Cadillac plans," high-deductible insurance plans that some believe are one of the reasons for high insurance costs. The plan would impose a 40 percent tax on insurance coverage in which premiums are more than $8,500 for an individual and $23,000 for a family. The Senate bill, however, targets the wealthy also, but by increasing the Medicare payroll tax on individuals who make $200,000 a year and couples who make more than $250,000.
The House, on the other hand, does not include a tax on "Cadillac plans" but it does impose an income tax on the wealthy. Under the House plan, there would be a tax surcharge of 5.4 percent on income over $500,000 in the case of individuals and $1 million for families.
Democrats in both chambers have been deeply divided over abortion language in the health care legislation. The House bill includes Stupak's amendment, which takes federal funding restrictions for abortion further with new language that cuts access to abortions for people who receive federal subsidies and those who purchase insurance through the health insurance exchange, a marketplace where people would be able to shop for and compare insurance plans. It also bans insurance companies participating in the exchange from offering abortion services.
The Senate includes slightly less restrictive language on abortion. In that version of the health care bill, states have the option of banning coverage in insurance plans brought in insurance marketplaces.
Democratic leaders in the House would be happy to concede to the Senate version -- liberal members of the party were unhappy with the abortion language inserted in the bill -- but Stupak told ABC News last week he will not vote for a bill that does not include his language. There are several anti-abortion Democrats in the House who insist on this as a condition to pass the bill.
"Our members are holding, so we will not pass if they are putting anything but a version of our language," Stupak said.
The Senate plan does not include the option of a government-run insurance plan, a thorny issue among Democrats. The plan initially had a public option in which states would have the choice of whether they wanted to participate. But Democratic leaders did away with that provision to appease lawmakers such as Nelson and independent Sen. Joe Lieberman of Connecticut.
The House health care bill, however, includes a public option in what becomes one of the biggest health care policy differences between the two bills. Under the House's public option plan, the government would negotiate rates with insurance companies instead of setting fees, as it does in Medicare.
At least 50 Democrats in the House are on the record as saying they will not vote for a bill without this option while Nelson and Lieberman have refused to support a bill that does include a public option.
President Obama Monday tried to downplay the differences over the public option, saying that debate is not the most important aspect of the bill.
"This is an area that has just become symbolic of a lot of ideological fights. As a practical matter, this is not the most important aspect to this bill -- the House bill or the Senate bill," the president said in an interview with American Urban Radio Networks, adding that "the Senate and the House bills are 95 percent identical."
Obama, who had initially pushed for a public option, spoke of the plan in the past tense.
"It was only going to apply to a few million people who were buying into the exchange," Obama said. "So it wasn't like suddenly everybody would just go out there and buy a government-run plan; most people will still get health insurance from their employers. What will happen is, is that if you don't get health insurance through your employers, you can then go to this what we're calling a health care exchange, get a subsidy and buy health insurance through that exchange."
ABC News' Jonathan Karl and Dr. Tim Johnson contributed to this report.