The amount of income needed to qualify for a mortgage is well below the median income in most parts of the U.S., according to NAR data.

NAR found that the national median family income was $61,000 in the first quarter. If a buyer wanted to purchase a home at the national median price, he or she would need an annual income of $34,700 if making a 5 percent down payment. A 10 percent down payment would lower the requirement to $32,900, while a 20 percent down payment requires about $29,300.

The information on qualifying incomes to purchase a median-priced single-family home on a metropolitan area basis assumes a favorable credit rating and an interest rate of 4 percent with 25 percent of gross income set aside for principal and interest.

The NAR report also found that 32 percent of home purchases paid all-cash in first quarter 2012, and investors, who make up the bulk of cash purchasers, accounted for 22 percent of all transactions in the first quarter.