Home buyers considering a government-insured mortgage should make some extra room in their budget.

In an effort to reduce a potential budget shortfall, the Federal Housing Administration will force homeowners to pay a monthly insurance premium for a longer period. This follows a decision this year to raise the amount of the premiums for all borrowers, the fifth such increase since 2009.

Although the increase in premiums should bolster the agency’s bottom line, it will make things more expensive for borrowers who depend on FHA-insured mortgages, which allows them to make a down payment as small as 3.5 percent of the home’s purchase price.

The insurance premium that buyers pay in addition to their monthly mortgage payment traditionally expires once 22 percent of the principal loan is paid — usually in the first few years of a mortgage. Now, all new loan-takers have to pay the monthly premium for at least 11 years and up to the entire duration of their mortgage, according to the rule that went into effect Monday.

The difference could mean years of paying hundreds of dollars extra a month, depending on the size of the loan.

Premium amounts vary for each homeowner and are calculated as 1.35 percent of the annual unpaid loan balance. For example, a $100,000 mortgage would have an annual premium of $1,350 in the first year, which would be charged on a monthly basis as part of the mortgage payment.

“This [the new rule] is going to hit hard in low income and middle-class neighborhoods,” said John Settles, a District-based mortgage consultant with Wells Fargo.

The government insurer backs more than $1 trillion in loans, or nearly 14 percent of the mortgage market. It is considered an affordable option for new home buyers, especially those who cannot afford a high down payment or have less-than-stellar credit history.

But there has been concern that facing growing losses from mortgage delinquencies, the FHA might need a taxpayer bailout. Earlier this year, President Obama’s budget estimated the FHA’s deficit could reach $943 million.

The amount raised from premium increases and other measures have not been enough, and the agency still faces a shortfall of more than $5 billion, FHA Commissioner Carol Galante said in written testimony before a Senate subcommittee Tuesday.

Settles said his clients were “upset, confused and frustrated” when he explained the new rules to them.

“I told them: ‘Nothing has changed about your situation, but if you buy the same house that you were planning to a month ago, it’s going to cost you more,’ ” he said.

The changes come at a tough time for many buyers, who are competing for a small inventory of homes amid surging prices. Buyers can still opt for conventional mortgage loans, but those loans typically require higher down payments, and many lenders are less forgiving of blemished credit histories.

Bloomingdale resident Blake Warenik and his fiancee are first-time buyers, shopping for homes in the District. They had their eye on a condominium unit in Takoma but were unpleasantly surprised to learn that the new rule could mean an extra $200 per month for an FHA loan for an extended period.

“Two hundred dollars a month is quite a lot to add on top of what’s already a high mortgage payment in this city, as well as utilities, transportation and condo fees,” said Warenik, 29.