"One reason FHA rates could be lower than conforming-loan rates is that Fannie Mae and Freddie Mac have added 'loan level price adjustments' and guarantee fees to their loans that lenders then pass on to borrowers in the form of higher rates," says Bostic.

Had Mel Watt, director of the Federal Housing Finance Agency, not delayed fee increases on Fannie Mae and Freddie Mac loans at the end of 2013, conforming interest rates would have risen more than they otherwise would have, increasing the spread between FHA and conforming and loans, explains Gumbinger.

Future of FHA mortgage rates

Many experts have forecast a rise in mortgage rates through the end of 2014. While FHA mortgage rates are expected to increase right along with their conforming counterparts, they should remain below conforming rates throughout 2014, especially if the G-fee and Loan Level Pricing Adjustment increases come back into play, says Gumbinger.

Despite the fact that FHA interest rates remain affordable, the rising cost of FHA insurance premiums and the stipulation that mortgage insurance must be paid for the life of FHA loan has led many borrowers to reconsider FHA loans in favor of conforming loans.

"The FHA increased its mortgage insurance requirements in order to shore up the cash reserves Congress requires the FHA to have," says Bostic. "FHA borrowers have a riskier profile so you'd naturally assume that the mortgage rates are higher, but the mortgage insurance requirement offsets the risk and keeps rates lower."

The importance of FHA jumbo loans

Like Fannie Mae and Freddie Mac, the FHA saw expanded loan limits to help offset a lack of mortgage credit availability during the housing crisis, helping to keep mortgage money available to audiences outside the relatively strict confines of GSE-backed loans. Both borrowers of modest means and those who are more well-to-do have found shelter in FHA-backed mortgages, and this is likely to continue.