Aetna Inc has decided not to reinstate or extend individual health insurance plans that are being canceled with the advent of the U.S. Affordable Care Act because the time frame is too short. Aetna is the largest insurer yet to announce a decision on how it would proceed across the United States after President Barack Obama said last month that insurers could extend these health plans under a temporary transitional policy. Aetna's move means that some consumers, who are required to have health insurance in 2014 or pay a fine, will need to buy a new plan for 2014. Aetna CEO Mark Bertolini made the comments at an investor meeting on Thursday.