(CNN) - Americans 18 to 29 are the least familiar with the Affordable Care Act, a new Gallup poll has found.
The latest numbers come just as the enrollment site, HealthCare.gov, saw a surge in visitors on Monday following a two-month scramble to fix it after a disastrous October launch.
The success of the Affordable Care Act, also known as Obamacare, depends on younger, healthier consumers to sign up for coverage.
Their premiums, according to proponents of the law, will help offset the costs of providing care to older people, who pay premiums as well but also use the health care system more.
Gallup found that 63% of those 18-29 respondents say they are "very familiar "or "somewhat familiar" with the law, while 37% say they are "not too familiar" or "not familiar at all."
The age group that reports the most familiarity with Obamacare is the 50-64 age range, with 77% of those respondents describing their knowledge of the law as "very familiar" or "somewhat familiar."
According to earlier Gallup polls, overall knowledge of Obamacare stayed much the same from late summer through November.
In mid-August, Gallup found that 68% of Americans surveyed were familiar with the law. That rose just slightly, to 72%, in late November.
Income also comes into play when it comes to familiarity with the law. Gallup found that 29% of Americans who make less than $90,000 a year are not familiar with Obamacare, compared with only 10% of those who make more than $90,000.
Gallup's latest polling also took into consideration how Americans feel about the new law.
According to Gallup, respondents who self-identify as Republican are more critical and more familiar with the law than Democrats who were surveyed.
Overall, Gallup found that 54% of American adults disapprove of the law, up from 49% in late August.
The Gallup poll was conducted Nov. 23-24, 2013, with 1,034 adults nationwide questioned by telephone. The survey’s sampling error is plus or minus 4 percentage points.
- CNN's Cassie Spodak contributed to this report.