Landrieu also said earlier Thursday she had not decided what she would do, but added, "I want to get to the debate. I am not trying to derail this bill."
According to the nonpartisan Congressional Budget Office, the provision would cost the federal government $100 million. Landrieu, though, said she believed it would provide her state with $300 million and said even that amount would not be all the funds Louisiana needs.
Reid, D-Nev., will need 60 votes to overcome procedural hurdles by Republicans and begin considering the bill, a prime priority for President Barack Obama. The Senate has 58 Democrats and two Democratic-leaning independents, and all Republicans are expected to vote "no."
Landrieu has said she wants health legislation that drives down medical costs and helps families and small businesses afford coverage. She has also expressed general opposition to establishing a government-run health insurance program, as Reid's bill would do, but she has left the door open for compromise.
In the interview, Landrieu said the extra money for Medicaid, the federal-state health care program for the poor, was "something that I asked for and I'm happy to say we're making progress on it."
The money in the bill is for 2011. Louisiana is already receiving extra Medicaid funds for 2010 under this year's economic stimulus program.
The section of the 2,074-page bill that provides the aid does not mention Louisiana by name. Instead, it describes several conditions -- such as all of its counties or parishes qualifying for federal assistance -- that apparently apply only to Louisiana, according to a Landrieu aide who spoke on condition of anonymity.
Louisiana's federal assistance for the program was cut after the devastation of Hurricane Katrina drove up average income in the state because of government aid and high-paying reconstruction jobs. The federal share of Medicaid aid is higher for states with lower average incomes.