Subprime lending, also called B-paper, near-prime, or second chance lending, is the practice of making loans to borrowers who do not qualify for the best market interest rates because of their deficient credit history.

There are many different kinds of subprime mortgages, including:

interest-only mortgages, which allow borrowers to pay only interest for a period of time (typically 5-10 years);

“pick a payment” loans, for which borrowers choose their monthly payment (full payment, interest only, or a minimum payment which may be lower than the payment required to reduce the balance of the loan);

and initial fixed rate mortgages that quickly convert to variable rates.

This last class of mortgages has grown particularly popular among subprime lenders since the 1990s. Common lending vehicles within this group include the "2-28 loan", which offers a low initial interest rate that stays fixed for two years after which the loan resets to a higher adjustable rate for the remaining life of the loan, in this case 28 years. The new interest rate is typically set at some margin over an index, for example, 5% over a 12-month LIBOR. Variations on the "2-28" include the "3-27" and the "5-25".