In a separate survey, the Kaiser Family Foundation and NBC found that just over half are worried about the healthcare law.
Nearly three-fourths said they were very or somewhat concerned that they would pay higher healthcare prices as a result of the program.
"I'm really confused, but one thing I know is I can't afford it," Earle Griffis, a commercial fisherman, told NBC.
The numbers highlight the challenge facing federal health officials as they attempt to enroll millions in the new health insurance exchanges over the next six months.
Confusion has plagued the Affordable Care Act since its passage. A survey by the Kaiser Family Foundation found this spring that nearly four in 10 weren't sure if the law remained on the books.
Oct. 1 marks a major milestone in implementation and comes as Republicans are seeking to stop the program in negotiations over how to keep the government running.
If the stalemate continues and the government shuts down Monday night, enrollment will still move forward starting Tuesday.
The surveys released Monday had some bright spots for the law's rollout.
More than three-quarters of adults were aware that they will be required to carry insurance starting next year, according to the Commonwealth poll, while three in five eligible adults said they were likely to take advantage of the new coverage options.
Another 68 percent expressed strong or partial support for the Medicaid expansion.
The KFF/NBC survey was conducted between Sept. 12-18 and involved 1,503 respondents, while the Commonwealth poll was taken from July 15 to Sept. 8 and involved 6,132 respondents.