By Sabrina Corlette, Justin Giovannelli, Ashley Williams and Kevin Lucia

Though open enrollment in the Affordable Care Act’s insurance marketplaces continues through February 15, December 15 was the last day for consumers in most states to actively enroll in a health plan and have that coverage take effect on January 1. Thanks to an automatic renewal process, coverage will continue for most of those who already had a marketplace plan and didn’t return to shop by this deadline. However, while auto-renewal can help people avoid a gap in their coverage, shopping for a plan is the best way for people to get good deal on coverage and maximize the value of their premium tax credit.

In the federally facilitated marketplace, those who are auto-renewed will have the dollar amount they were receiving in premium tax credits in 2014 carried forward into 2015. But because changes in plans, personal circumstances, and other factors will almost always dictate a different tax credit amount for next year, auto-renewal can also expose enrollees to an unexpected increase in premium or, in some cases, tax liability.

In our latest blog post for the Commonwealth Fund, we surveyed 17 state-based marketplaces about their approaches to coverage renewals and found that a number of them took advantage of the flexibility provided under federal rules to reduce consumers’ potential financial risk. Others, largely because of changes to their IT systems, required enrollees to return to the marketplace to maintain their coverage or financial assistance, thereby encouraging consumers to shop around for the best deal. You can read about the different state approaches – and their potential impact on consumers – here.