The health-care plan passed in March 2010 will not be what is ultimately implemented, according to former Aetna CEO Ronald Williams.
Williams told CNBC Wednesday the law will not work without changes.
"The one thing I believe is that the law as it was passed will not be ultimately what gets implemented partly because of the reality of confronting the implementation process and discovering that while the intention was good, in reality, it just won't work," Williams said.
Williams, who left Aetna in 2010, is a member of the President's Management Advisory Board. The board's mission is to incorporate business practices into the federal government to increase efficiency.
Williams said business uncertainly can negatively affect the business environment. He stressed the importance of creating greater clarity on taxes and regulation and also increasing consumer confidence as key ingredients for business growth. He cited health care regulation as an example of the need for greater clarity regarding new regulations.
"I think businesses don't really understand how their business models will be impacted by the health-care regulations," Williams said.
Currently, some companies with part-time employees are unclear about whether they are required under the new law to provide these employees with health-care coverage, he said.
Since its passage the health-care law has been a highly contested issue in Congress and one that is already being hotly debated by candidates as they vie for the presidency in the upcoming 2012 election.
Although some have questioned the legality of the landmark legislation, in June a U.S. appeals court upheld the constitutionality of the law.
In addition to Williams' role on the advisory board, he is also a director of American Express, Boeing and Johnson & Johnson.