The study published in the Proceedings of the National Academy of  Sciences found that mortgage lenders were  73% more likely to deny same-sex couples a home loan and charge them more for it. This was compared to heterosexual couples with the same financial worthiness, according to an analysis of national mortgage data from 1990 to 2015. On average, same-sex couples were given inferior terms when they were approved for a loan. They  paid 0.2% more in interest and fees - $86 million a year. 
It is legal for lenders to charge higher fees if there is greater risk, but the study found same-sex couples slightly are better regarding possible defaults, according to Lei Gao, an assistant professor at Iowa State University’s Ivy College of Business and co-author of the study.  
The study's researchers said their findings show the need: (1) to include sexual orientation as a protected class under federal lending laws to guarantee same-sex couples equal access to credit, and (2) that credit monitoring agencies should investigate unfair lending practices. A change in the law in necessary because while the Fair Housing Act and the Equal Credit Opportunity Act outlaw discrimination against borrowers on the basis of race, color, religion, sex or national origin, they do not include sexual orientation.