The Obama Administration has delayed the individual mandate until the federal health exchange website, healthcare.gov, is fixed. The delay also fixes the problem where people will no longer be individually taxed even if they sign up for coverage at the tail end of the open enrollment period (October 1-March 31st).
Prior to the delay, an individual needed to sign up for a health care plan by February 15th.
Megan McArdle’s article in Bloomberg explains why:
Basically, the Patient Protection and Affordable Care Act says that in order to avoid paying the fine for being uninsured, you have to be insured by the end of March. But insurance policies begin on the first day of the month, which means that you need to buy insurance by February. And because it takes a couple of weeks to process a policy, in practice, you need to purchase by Feb. 15. If you buy insurance after that, you will still be insured — but you will also need to pay a penalty.