Support for the law has also dropped slightly, from 44 percent to 40 percent.
Eleven percent of those who oppose the law say it's because they lost their insurance -- something Obama had said wouldn't happen. Another 16 percent said the law is not working or was poorly planned, and 7 percent said they oppose the law because Obama misled Americans about it.
The poll comes on the heels of a Quinnipiac University poll on Wednesday which also showed a drop in support for Obamacare. Despite weeks of rough headlines, these are the first two polls to show such a drop.
The Quinnipiac poll also showed Obama's approval rating hitting a new low.