"I'm very worried about the regulations that are going to be coming out over the next several months," he added, noting that his concern was based on feedback from constituents and businesses. "I really think it's a danger to the future of the law if the regulations are not well thought out and minimally intrusive in order to achieve their ends."
Though King was elected in 2012 and was not able to vote for the healthcare reform law, he said he supports the Affordable Care Act and caucuses with the Democratic Party.
King's major concern, he said, is regulators who don't have to answer to the public for their actions.
"We've created in this country what amounts of a fourth branch of government that's very close to being entirely unaccountable," King said on Thursday. "It's all checks and no balances."
King said he fears that some overly intrusive rules will give opponents of the law "ammunition."
"I just worry that the regulatory burdens will be so much that it will create a backlash, even amongst those businesses which won't be subsequently affected."
King's comments match concerns of Democrats in Congress who worry that a problematic roll out of key features of the law could hurt their odds ahead of the 2014 election and prevent the party from controlling Congress for the remainder of President Obama's term.
One such Democrat who distanced herself from the law was Elizabeth Colbert Busch (D), who denounced the law as "extremely problematic" before she lost a House special election to former South Carolina Gov. Mark Sanford (R).
At a press conference in late April, Obama admitted that "even if we do everything perfectly, there will still be glitches and bumps" in the law's implementation.
By October, the administration is seeking to set up new insurance exchange markets, and this summer it plans to enlist "navigators" to guide consumers through their insurance options in those marketplaces.
In April, Obama called it "a big undertaking."