Clinton says Obama should "honor the commitment that the federal government made to those people and let them keep what they got."
Obama has come under pressure in recent weeks as millions of Americans started receiving insurance cancellation letters. The president had repeatedly said people would not be forced to change their insurance under the new law.
The White House says it is working on changes that would ease the impact of the cancellations for some people. But the fixes under consideration are administrative actions, not congressional changes to the law.
Clinton spoke in an interview with the website www.OZY.com, posted Tuesday.