On March 23, 2010, President Barack Obama signed the Patient Protection and Affordable Health Care Act. The act was passed by Congress the previous day after over a year of debate. The bill was significantly amended a week later to reconcile the differences between House and Senate Democrats. The final legislation prohibits insurance providers from denying coverage to children because of pre-existing conditions and from dropping individuals from insurance plans because of illness. It requires all insurance providers to provide a rationale for proposed increases in premiums and requires all Americans to purchase health insurance by 2014. The legislation has sparked significant nationwide controversy. Several federal district courts have split on the issue of the law's constitutionality, with some upholding it, and some striking it down.