Increased value: Depending on who holds your mortgage, your home will have to have increased in appraised value to the point that you now have 20 to 25 percent equity, to drop PMI.

For example, Fannie Mae says 20 percent, but Freddie Mac says 25 percent in years 2-5 of your loan, unless you've made a major improvement to your home such as remodeling a bathroom, in which case 20 percent will do.

Your loan servicer can tell you how far away you are from meeting the 20 to 25 percent equity. That will tell you how much your appraisal would have to be. By checking newspaper real-estate ads or talking with a real-estate agent, you can tell whether your home is likely to appraise that high.

Appraisals: Almost all lenders will require you to prove your home's increased value with a full real-estate appraisal. It must include photos and a check of comparable sales prices in your area. A market analysis by a real-estate agent will not do. Some lenders will accept the county tax assessment, but many will not.

For example, University Savings and Pioneer Bank never accept a tax assessment, while Washington Mutual Savings will review a tax assessment on loans that are five or more years old.

Your lender should provide you with names of approved appraisers or, in some cases, may sendan in-house appraiser or arrange for a private appraiser to be sent to your home.

If you have had a full appraisal recently - to qualify for a home equity loan, for example - you may be able to use it even though the appraiser isn't on your lender's approved list. Often lenders are willing to have their in-house experts review the appraisal. Ask.

Expect to pay $275 to $500 for an appraisal, depending on the value and location of your home.

Savings: To figure out if you will save more than the cost of the appraisal by dropping PMI, multiply the amount of your monthly PMI premium by the number of months you have left to pay PMI. Again, your loan-servicing department can help you figure this.

As a rough guide, consider that PMI on $130,000 - the average loan amount today in King and Snohomish counties - would be $55 a month, or $660 a year, says Pam Kerns, regional underwriting manager of United Guaranty Corp., a private mortgage insurance company. That would mean you'd recoup the cost of an appraisal in less than a year.

Elaine Vincent of Pioneer Bank says it takes approximately 10 years to end PMI by making regular payments. So if after one year of payments on the $130,000 loan you could shave off nine years of PMI, you'd save something like $5,500-$5,800 after deducting the appraisal fee.

Not sure how much your PMI is? Check your original mortgage papers. Note, says Shari Spiess, account representative with PMI Mortgage Insurance Co., that PMI changes over time: it's one rate in your loan's first year; lower in year 2-10; lower still after year 11.

Some lenders also send a yearly statement that lists your PMI.

(If you've financed your PMI as part of your loan, check with your lender. Different conditions may apply.)

Written request: Send any request to drop PMI in writing to your lender; Marcia Kindig, president of Mortgage Consultants Ltd., suggests you send it certified. It will normally takes 30-60 days for the PMI to be dropped.

Appeal: If you meet the lender's requirements, you shouldn't be turned down. But if your loan is owned by an investor who refuses to drop insurance based on a new appraisal, or if your appraisal is simply rejected, you have several options.

You can send a letter to the firm you send the payments to and request a review of your case.

Kindig of Mortgage Consultants suggests that, if it's a matter of a recalcitrant investor, you contact your private mortgage-insurance company and ask for help. If asked, that company can contact the investor and say that its recommendation is that the insurance be dropped, says Kerns of United Guaranty. But, Kerns says, they're more likely to do that if asked by a lender to contact a secondary investor, as they usually don't deal directly with individuals.