The health insurance mandate survived a U.S. Supreme Court challenge and has now been in effect for a year. In 2015, the penalty for those who don't comply, or don't have an exemption, could double or even more than triple.

That's something that those putting off buying coverage should keep in mind as the days dwindle to buy insurance that begins on Jan. 1.

The mandate is the Affordable Care Act's personal responsibility plank. It's intended to help end cost-shifting to those with insurance when those without get hurt and don't pay their bills. Those who complain about the mandate miss the point about correcting a system that rewarded risk-takers while penalizing those responsible enough to get coverage.

The year to come brings a steep increase in the financial penalty for opting out. In 2015, the fine climbs to 2 percent of household income above a tax filing threshold, or $325 a person, whichever is higher, according to healthcare.gov. Children younger than 18 are assessed half of that fine.

For 2014, it's 1 percent of income, or $95 a person ($47.50 for children), whichever is the greatest.

The mandate's teeth continue to sharpen in subsequent years. In 2016, it's 2.5 percent of household income or $695 a person in 2016. According to healthcare.gov, you pay the penalty when you file tax returns. If you don't pay, the sum is deducted from your return.

Healthcare.gov provides a list of hardship exemptions. But the ACA also provides new financial aid, and consumers may be pleasantly surprised to find that coverage is more affordable than they thought.