From the Summary: "The federal government supports homeownership in different ways. One of the main ways is through programs or support from quasi-government entities that promise lenders or investors that if a homeowner defaults on a covered mortgage, the lender or investor will still receive some--or all--of the amount it was owed. These types of guarantees can support homeownership by making private lenders more willing to offer certain types of mortgages. Additionally, they can increase the number of private investors who are willing to invest in mortgages, thereby increasing the amount of capital available for mortgage lending. The details of the programs differ, but most have limits on the size of mortgages that are eligible. This report contains brief program descriptions and discusses the maximum mortgage amounts for each."
CRS Report for Congress, R44826
Congressional Research Service: https://crsreports.congress.gov/