Two years after Superstorm Sandy, State Farm agent Jen Dunn is busy explaining new insurance math to her customers in upstate New York. Instead of the dollar-amount deductibles they have been used to for years, she is now writing their policies based on percentages.

For many, it means turning the typical $500 deductible into 1 percent of the insured value - for a $250,000 house, that means a gasp-producing $2,500.

"My clients who have been offered this initially say, 'I don't like this,'" Dunn says. But then she explains that the higher amount is usually offset by a lower annual premium. If they go years without a claim, they can save in the meantime.

Jason Corbett, 39, who lives in central Georgia, is using a 1 percent deductible. Because Corbett's rural home is valued at slightly less than $200,000, it was a better deal than a flat $1,000 deductible. The difference between the two deductibles was only a couple of hundred dollars. However, he saved money by lowering his premium, so over time the difference in his out-of-pocket costs will be negligible.

If he had a $300,000 home and the deductible was double what he pays now, "that would be a different decision," says Corbett, who writes a personal finance blog ( ) .

State Farm, the largest U.S. property and casualty insurance company by market share, says a "significant" number of its policies now have percentage deductibles. Other carriers, like Allstate Corp, USAA and Nationwide, also offer the option to consumers in certain states, but the prevalence is not yet tracked nationwide. The practice is near-universal in Texas at this point, according to that state's insurance office.

With a percentage deductible policy, things are a little different than the old-fashioned flat rate. Here are seven things you need to know:

1. Do not be afraid of high deductibles

You might be used to $500, but a higher deductible could actually be better for you.

"It's a very smart move to buy high deductibles if you can afford it," advises J. Robert Hunter, director of insurance for the Consumer Federation of America.

The main reason? Every claim you make against your homeowners insurance can raise your rates. One claim pushes it up an average of 9 percent and two claims will raise it by 20 percent, according to a recent study by So you want to pay out of pocket for small claims anyway.

2. The 1 percent deductible is not a percentage of your loss

The new terminology makes people think of health insurance, but homeowner claims do not work that way, says Jim Gavin, director of insurance information services for the Independent Insurance Agents of Texas trade group.

Rather, the out-of-pocket deductible you have to pay before the company will cover any claims is based on a percentage of the insured value of your home - which is not the market value or the appraised value, but the cost of replacing your home should it burn to the ground and need to be rebuilt.

For example: if a kitchen fire damaged your $250,000 home with a 1 percent deductible, and it cost $5,000 to repair the damage, you would receive a check from the insurance company for $2,500 after paying the other half yourself.

3. Your out-of-pocket costs will regularly increase

Your $500 deductible stays flat forever, but a percentage deductible will go up incrementally over time as the insured value of your home rises.

Some homeowners may not even notice this, like Will Harvey, 34, of Tyler, Texas, who is five years into a 1 percent policy on his home. "If it went up, it wasn't enough for me to remember it," he says.

4. You will still have other deductibles on top of the basic rate

Many homeowners have add-on clauses like a 5 percent hurricane deductible that is common in coastal areas, or 2 percent for wind and hail damage. Many states require separate coverage for earthquakes and floods.

Those all still apply on top of the basic coverage for fire and theft, says Amy Danise, editorial director of So if you have any damage that is caused by a specified risk, you will have to pay out of pocket first for that.

5. Your might be able to pay down your percentile

If 1 percent is too much for you, you may have the option to accept a higher premium to lower out-of-pocket costs - going from 1 percent to half a percent or some other fraction. The value to you depends on how much your house is worth and how much you can afford to pay out of your savings if something goes wrong, says State Farm's Dunn.

6. You can still shop around

Even in Texas, where almost every company offers a deductible of at least 1 percent, or sometimes up to 1.5 or 2 percent, some carriers still do things the traditional way. Texas insurance agent Criss Sudduth says the customers who might benefit more from a flat-fee policy are those whose premiums do not actually go down despite the percentage policy - either because the weather risks are too high or because their personal credit is bad.

7. You should still figure out your dollar amount

After years of hearing complaints from consumers who are confused, the Texas legislature passed a bill recently requiring carriers to explain what the percentage deductible translates into, in dollars.

In other states, if your carrier does not do this, you should find out the information yourself and write it on your declarations page, says Deeia Beck, public counsel and executive director of the Texas Office of Public Insurance Counsel.