Many homeowners have taken advantage of low interest rates by refinancing their properties which allows for lower monthly payments, less money paid over the life of a loan, and the opportunity to borrow against equity. Unfortunately, some homeowners can't refinance due to the underwriting rules used by many mortgage companies. For these homeowners, one of the best alternatives to the standard mortgage refinancing process is a home refinance through the Home Affordable Refinance Program, commonly known as the HARP stimulus.

The purpose of HARP is to give struggling homeowners more mortgage refinancing options, allowing them to move into more stable mortgages. The U.S. Government basically supports the homeowner's credit so that mortgage companies can allow them to refinance. It's a particularly powerful program right now, as the housing market crash has led to the best mortgage rates in the United States in recent history.

Some homeowners aren't able to qualify for HARP, however. The program is only for struggling homeowners but not homeowners who have been late on their payments. A single late payment may mean ineligibility. HARP is also meant for homeowners whose mortgages are "underwater," meaning that the remaining balance on the mortgage exceeds the value of the property. However, revisions to the program in 2011 allow for a mortgage with an 80 percent loan-to-value ratio to qualify.

Homeowners must also complete a questionnaire and provide proof of income before they're qualified for HARP. When they're approved, they can get the best mortgage rates possible by comparing rates from different lenders, as once they've started the mortgage refinancing process the HARP stimulus will remove some of the lender's risks.

The HARP program is usually used to get lower mortgage rates, but it can also be used to move from an unstable loan to a stable loan. Variable-rate loans are considered unstable as costs can rise dramatically, so homeowners who qualify from HARP may be able to move from a variable-rate mortgage to a fixed-rate mortgage, regardless of which mortgage technically has the better rate.

While some homeowners find it difficult to apply for HARP and others are simply ineligible, the program does provide a strong resource for certain homeowners. It's one of the best ways for people with underwater mortgages to improve their monthly payments and get stable mortgages that will build up equity.