Under the Affordable Care Act, almost everyone is required to be covered under a health insurance plan, or pay a penalty. And that penalty is set to rise steeply this year.

You can avoid the penalty for this year if you were covered by an employer's plan for most of 2015. Alternatively, you needed to enroll in an Obamacare-compliant plan purchased on an exchange no later than February 2015. Enrolling in a plan now won't help you sidestep the penalty for being uncovered for most of 2015.

To avoid the penalty for 2016, if you won't be covered under an employer's plan, you'll need to enroll in a health plan on an exchange in the first two months of 2016.

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People who weren't covered under a compliant health plan in 2015 or didn't meet some specific exemptions will have to pay what amounts to a fine when they file their 2015 tax return. The government has two ways of calculating what you'll owe in 2015. That's the greater of $325 for each adult and $162.50 for each child, not to exceed $975, or 2 percent of your family's adjusted gross income.

The most you can be fined is capped at the national average cost of a bronze-level health plan available on the exchanges. For 2015, that's $2,570 for singles and $5,140 for families.

According to this calculator, the penalty in 2015 for a single individual whose adjusted gross income is $75,000 would be $1,294. The penalty for a married couple (no kids) with 2015 income of $100,000 would be $1,588.

In 2014, the penalties in these examples were $649 and $797, respectively. So, the increase in 2015 is about 100 percent. And in 2016, these penalties are set to rise approximately 25 percent. That's the ACA's design -- to increase the penalty cost of going without health insurance to create a greater incentive to buy coverage for 2016.

Note that some people are exempt. This includes those who've been uninsured for three months or less in 2015 or lived abroad for more than a year. Here's a complete list of these exemptions.

Also, some people can qualify for a hardship exemption. This includes those who are homeless, filed for bankruptcy, experienced a natural disaster that damaged your home or who've experienced the death of a family member.