NEW YORK (CNNMoney.com) - Interest rates are on the rise, and so are monthly payments if you have an adjustable-rate mortgage.

Homeowners with these kinds of mortgages may be concerned about what that means to their bottom line.

Mortgage Rates 30 yr fixed 3.80% 15 yr fixed 3.20% 5/1 ARM 3.84% 30 yr refi 3.82% 15 yr refi 3.20% Find personalized rates:   Rates provided by Bankrate.com.

In today's tips we're going to tell you the smart moves you should make if you have an ARM.

The bottom line here is that rising interest rates mean ballooning payments. And since ARMs make up about 25 percent of mortgages, it may pose a widespread problem.

This year, it's estimated that $330 billion worth of ARMs will adjust upward. On a $200,000 loan that goes from 4.5 percent to 6.5 percent, monthly payments will increase from $1,013 to 1, 254 - a difference of $241 a month or almost $3,000 a year.

If you have a quick-changing mortgage, like an option ARM, you'll want to think about refinancing. The days of cheap money are over, says Brad Inman of Inman News.

To buy some time, get into a 5-year or a 7-year hybrid adjustable rate. You can't lose. The average rate on an option ARM today is 6.75 percent, says Bob Moulton of Americana Mortgage. But rates on 5-year or 7-year hybrid ARMs are 6 percent to 6.25 percent.

You'll want to go back to your original lender and tell them you want a safer loan. Make sure you also look at the cost of refinancing. Generally it costs about a percentage-point or a percentage-point and a half of your original loan.

So refinancing a $200,000 mortgage could cost up to $3,500.

Three years ago, HELOCs were the darlings of people wanting to make some home improvements. But that was 16 Fed rate hikes ago. Today HELOCs are very costly - and they're slated to get even more expensive if the Fed follows through with another rate hike this month.

At 8 percent today, you're paying $666 a month on a $100,000 line of credit. Three years ago, you were paying half that.

If you can, refinance into a single 30-year fixed loan. This will eliminate all uncertainty with the fate of future rates. You can also ask your lender about some other HELOC products that have fixed rates for a certain amount of time.

And of course, if it's at all possible, pay off your HELOC. But be careful. Prepayment penalties can be as high as $6,000.

Americans spend most of their money on their homes and their cars. You don't want to consolidate all of your other debts (credit card and student loans, for example) into your mortgage because it stretches out the life of your loan and makes it more expensive in the long run.

Think about it: You don't want to be using a 30-year mortgage to be paying off a car that's going to last six years.

A $10,000 debt on your credit card is going to cost you over $12,000 in interest alone if you stretch out the payments, according to Doug Flynn of Flynn Zito Capital Management.

Everyone and their brother are going to sell you products that promise to take away your pain. You have to be vigilant. Don't bother with ads that offer rates lower than 4%, says Moulton. In today's environment, that's just not realistic. If an ad touts that you won't have to pay closing costs, or you don't need any money down, you should be skeptical. There are always strings attached.

Make extra sure you're not paying more than you need to every month. Re-evaluate your Private Mortgage Insurance payments. You're probably paying this monthly fee if you put less than 20% down on your home.

If you took out your loan after July 1998 and you have paid off about 22% of the loan already, your lender must cancel your PMI payments. But it's up to you to go to your lender and prove your gains.

If you live in an area that has appreciated significantly, check recent sales in the neighborhood. If you've been paying off your mortgage diligently or homes in your area are going for well above what you paid for your home, it's worth your while to get a re-appraisal from your lender. It may cost you around $350, but if you can get out of paying hundreds of dollars each month for PMI, it'll be worth it.

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