This invention concerns a Shared Appreciation Mortgage (SAM), that is an arrangement where a customer enters into an agreement with a lender to share the equity in a real estate property. In a first aspect the invention is a method for financing real estate employing a Shared Appreciation Mortgage. The method involves a lender indicating areas where they will employ shared appreciation mortgages to finance a purchase of real estate properties. A customer seeks approval from the lender for the purchase of a real estate property at a price in one of the areas. After approval the customer enters into a contract, loan and mortgage arrangement as well as a residential purchase contract containing an obligation for the lender to pay to the customer an amount equal to the outstanding second loan immediately before the property is sold in order to purchase an interest in the property so that the lender and customer jointly own the property at the time of sale. In a second aspect the invention is a Shared Appreciation Mortgage. In a third aspect the invention is a real estate property purchased by a Customer. In a fourth aspect the invention is a financial security.