"Undoubtedly, there will be some mistakes and hiccups" as major pieces of the law fall into place later this year, Obama said Friday.
Most of the law's biggest provisions will take effect between Oct. 1 and Jan. 1, 2014.
"I'm here to tell you, I am 110 percent committed to getting it done right," Obama said.
Public polling shows the healthcare law remains unpopular — just 35 percent of those polled in the most recent Kaiser Family Foundation tracking poll said they have a favorable opinion of the law, while 40 percent had an unfavorable view.
That's a major concern for Democrats ahead of a midterm election that historically goes against the president's party. Republicans are hoping to add to their advantage in the House, and to retake the Senate.
Obama, for his part, is hoping to buck history. If Republicans gain congressional seats next year, his years as a lame-duck president are likely to begin immediately. But by gaining seats — and especially by winning back the House — Obama could give himself a chance to add to his record in the last two years of his term.
For more on Obama's remarks, click here.