A conforming mortgage is one that, literally, conforms to the mortgage guidelines as set forth by Fannie Mae and Freddie Mac.

Conforming mortgage guidelines are Fannie’s and Freddie’s eligibility standards; an underwriter’s series of check-boxes to determine whether a given loan should be approved.

Among the many traits of a conforming mortgage is “loan size”.

Each year, the government re-assesses its maximum allowable loan size based on “typical” housing costs nationwide. Loans that fall at, or below, this amount meet conforming mortgage guidelines. Loans in excess of this limit are known as “jumbo” loans.

Between 1980 and 2006, as home values increased, conforming loan limits did, too, rising from $93,750 to $417,000. Since 2006, however, despite falling home prices in many U.S. markets, the conforming loan limit has held steady.  This will remain true for 2012 as well.

In 2012, for the 7th straight year, the national, single-family conforming mortgage loan limit will remain at $417,000.

The complete 2012 conforming loan limit breakdown, by property type :

• 1-unit properties : $417,000
• 2-unit properties : $533,850
• 3-unit properties : $645,300
• 4-unit properties : $801,950

However, there are some areas nationally that have earned ”loan limit exceptions” based on the local median sales prices. These areas are known as “high-cost” areas and loan limits within these regions range from $417,001 to a maximum of $625,500.

Some examples of high-cost areas include San Francisco (along with a most of California), New York City, and most of Hawaii and Alaska. Nationally, there are approximately 200 such “high-cost” areas.

Verify your local conforming loan limit and loan limits across Washington State via the Fannie Mae website. A complete county-by-county list is published online.

For homeowners in high-cost areas nationwide, conforming and FHA loan limits have dropped by as much as 14 percent.

Effective October 1, 2011, the temporary mortgage loan limits that allowed for non-jumbo loan sizes of up to $729,750 are no longer.

$729,750 is above the “normal” loan limit of $417,000.

The elevated limits were put in place in 2008 as the economy and financial sector entered its crisis. At the time, there was little private money to serve buyers and would-be refinancers whose loan sizes exceeded Fannie Mae and Freddie Mac’s maximum $417,000 loan limits.

For most people whose loan sizes exceeded that threshold, mortgage financing was unavailable. There were no lenders to back the loan size.

This was of particular importance in places such as New York City, Los Angeles and Washington, D.C. where home prices routinely top $1 million. For people in these areas, unless they had a downpayment that could lower their respective loan sizes to $417,000 or lower, mortgages were mostly unavailable.

Congress recognized this and, as a result, gave Fannie Mae and Freddie Mac temportary authorization to purchase and securitize home loans of up to $729,750 in value, depending on where the subject property was located.

The program helped housing, leading Congress to pass more permanent, location-specific loan limits. Later that same year, Congress passed the Housing and Recovery Act of 2009 which, in part, made high-cost loan limit pricing permanent, albeit at $625,500.

The $729,750 temporary limits expired Friday, September 30, 2011. Today, the maximum allowable conforming loan size is $625,500.

If you live in a high-cost area, therefore, take note. Mortgage rates may be low, but the amount of loan for which you qualify may be less than you expect, and you may find yourself ineligible.

The complete list of high-cost areas is available online.

If you live in a high-cost area, keep an eye on your calendar. Effective October 1, 2011, temporary conforming loan limits will be lowered nationwide. Perhaps by as much as 14 percent.

These limits range up to $729,750 currently.

“Temporary loan limits” were enacted as part of the government’s 2008 economic stimulus package. At the time, the financial sector was entering its crisis and private mortgage lending had all but disappeared. Financing was scarce for both homeowners and home buyers for whom loan sizes exceeded Fannie Mae and Freddie Mac’s national $417,000 limit — even for those with excellent credit and income.

The issue was exacerbated in places like New York City where local home prices routinely topped $1 million. Buyers unable or unwilling to bring a substantial downpayment to closing (i.e. $600,000 or more) found themselves without financing.

The February 2008 package addressed this issue, using a math formula to change loan limits in Tumwater and nationwide. The government assigned to each U.S. metropolitan area a temporary, new loan size limit equal to 25% greater than its respective median home sale price, not to fall below $417,000, and not to exceed $729,750.

Then, later that same year, the Housing and Recovery Act made “high-cost areas” permanent, but with a reduced 15% increase to median home prices, and loan sizes not to exceed $625,500.

These new limits take effect October 1, 2011 — one day after the temporary limits expire.

If you live in a high-cost area, therefore, take note. Mortgage rates may be low, but the amount of loan for which you qualify may be less than you expect, and you may find yourself ineligible.

Whether you’re planning a refinance or a purchase, keep an eye on the calendar.

The complete list of high-cost areas is available online.