The United States Supreme Court ruled on June 28, 2012 that the individual mandate is constitutional.
The penalty for not having insurance will either be:
$95 or 1 percent of a person's income, whichever is greater in 2014
$325 or 2 percent of income in 2015
$695 or 2.5 percent of income in 2016
Beyond 2017 & 2018, the penalty will be based on the 2016 amounts plus an inflation adjustment. The penalty for dependents under the age of 18 is one-half of the individual amount. Some individuals may qualify for an exemption and will not be required to have coverage or pay a penalty. Individuals whose religious beliefs conflict with the acceptance of the benefits of private or public insurance and those who do not have an affordable health insurance coverage option available are two examples of individuals falling into this category.
Starting with the 2019 plan year (for which you file taxes in 2020), the individual mandate no longer applies.