Conservative activists are divided over the bill. Club for Growth and Heritage Action oppose it, because they oppose federally run high-risk pools and do not believe Congress should pour more money into a program that has already burned through its budget faster than expected.
FreedomWorks and Americans for Tax Reform are among the conservative groups supporting the legislation.
The healthcare law created high-risk pools as a temporary option for people who have been denied coverage because of a pre-existing condition. The pools expire in 2014, when it becomes illegal for insurance companies to deny coverage based on a pre-existing condition.
The Obama administration has stopped accepting new enrollees into the high-risk pools to ensure that the program's budget is able to cover the medical bills of people who are already enrolled.
Republicans support government-funded high-risk pools as an alternative to requiring insurers to cover those who are ill. The bill up for a vote Wednesday would move $4 billion into ObamaCare's high-risk pools. The money would come out of the law's prevention fund, which Republicans decry as a "slush fund."
"Separately, we remain strongly opposed to the Prevention Fund, and hope that House leaders will offer up a bill that terminates it and uses the savings to reduce the deficit," Club for Growth said Wednesday.