A little-noticed line in the Florida Legislature’s latest attempt to fix the state’s fractured home insurance market promises to have big impacts on more than a million Floridians. It will force them to also buy flood insurance — even if their homes aren’t in designated flood zones.

The provision, included in a sweeping insurance bill passed late last year, will make flood insurance mandatory for any homeowners with hurricane wind policies from Citizens Insurance, the state-run insurer of last resort. At minimum, that’s likely to add hundreds of dollars a year to the insurance bill.

As the mandate is phased in over the next few years, it could affect 1.2 million current Citizens policy holders, who will be required to get flood insurance no matter where they live or see their coverage canceled.

It also will apply to any new Citizens customers, with some of them impacted as early as April 1. And there could be plenty of those as private wind insurance costs continue to skyrocket and more companies go belly up, leaving Citizens the best option.

“I haven’t seen a sweeping requirement like this anywhere else,” said Laura Lightbody, project director of the flood-prepared communities program at the Pew Charitable trust. “It’s a huge deal. There have been pie-in-the-sky calls for mandatory flood insurance for anyone who owns a home, so it’s a really big deal for a state that currently does represent a large amount of the policies under the flood insurance program, which is a big indicator of risk.”

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The new policy could go a long way toward addressing Florida’s massive gap in flood insurance, but it will also drive up costs for many homeowners already facing spiraling insurance bills.