If your home falls in a high-risk flood area and you have a mortgage from a federally regulated or insured lender, your lender is legally mandated to require you to have flood insurance, FEMA says. Typically, that's not the case if your home falls in a moderate-to-low risk area. However, a lender may require you to hold flood insurance at any time — even if the company is not legally mandated to do so, according to FEMA.

To obtain an NFIP flood insurance policy, your community must participate in the program. Most communities participate, but not every municipality across the country does. You can check whether your community participates in the NFIP Community Status Book (click on your state, and then search through the alphabetical listing of communities to see if yours is on the list).

While flood insurance is offered through the NFIP, policies are sold and administered by private insurance companies. Most policies don't take effect until 30 days after signing, so it's a good idea to consider purchasing coverage before storm season is upon you. Talk to your insurance provider about your flood insurance needs.