Real estate agents arrive at a brokers tour showing a house for sale in San Rafael, California. Getty Images

When Dr. William Ngo was shopping for his first home two years ago, he ran into a problem: He got rejected for a mortgage because he had about $250,000 in student debt and little savings. So the surgeon applied for a loan specifically designed for doctors that came with a higher interest rate but no money down, and just a future work contract as proof of income. Mortgages tailored to doctors have grown more popular in the last few years, according to the lenders who offer them. Bank of America said it has seen the dollar volume of physician mortgages it issued between 2008 and 2017 increase ninefold because of greater awareness from consumers. Smaller banks also report increases. Stillwater, Oklahoma-based Bank SNB, owned by Simmons First National, issued $50 million in physician home loans last year and is on track to double that amount this year, said Drew Daniels, a mortgage sales manager who launched the loan program.

Meanwhile, SunTrust Banks' largest subsidiary, based in Atlanta, has doubled its staff dedicated to serving physicians and medical practices over the last four years as it sees more demand for the mortgages, according to a company spokesman. And LeverageRx, a website that compares physician mortgage lenders, has seen a 51 percent increase in doctors searching for the loans year-to-date, compared with the same period last year. High salaries and a stable job market relative to other professions make doctors lucrative and low-risk customers for banks that hope to sell them other products down the road. The average physician salary this year is $299,999, according to Medscape's annual survey of 20,329 doctors across roughly 30 specialities. "You're a student, emerging physician, hit with all this debt. You have a lot of future upside," said John Cross, divisional sales executive at Bank of America. "If you provide a mortgage solution at the beginning of their career, … from there it turns into all kinds of other conversations." Bank of America stopped offering the loans in 2009 during the housing crisis but brought them back in 2010 with stricter borrowing guidelines, Cross said. For instance, doctors have to put at least 5 percent down instead of zero. For new physicians, the loans can offer a fast path to home ownership for those who wouldn't be approved otherwise. Last year, the median student debt for new medical student graduates was $190,694, according to the Association of American Medical Colleges. The loans are also designed for dentists, while some also cover veterinarians, optometrists, nurse practitioners and physician assistants.

William Ngo’s home in Knoxville, Tennessee Source: William Ngo

The catch: Higher interest rates