The Pending Home Sales Index, a forward-looking indicator based on contract signings, inched up 0.4 percent to 107.6 in March from a downwardly revised 107.2 in February. Even with last month's increase in activity, the index declined on an annualized basis (3.0 percent) for the third straight month.

Lawrence Yun, NAR chief economist, says contract activity is moving sideways and not breaking higher despite the strong job-creating economy. "Healthy economic conditions are creating considerable demand for purchasing a home, but not all buyers are able to sign contracts because of the lack of choices in inventory," he said. "Steady price growth and the swift pace listings are coming off the market are proof that more supply is needed to fully satisfy demand. What continues to hold back sales is the fact that prospective buyers are increasingly having difficulty finding an affordable home to buy."

Added Yun, "As anticipated, the multiple winter storms and unseasonably cold weather contributed to the decrease in contract signings in the Northeast."

"Much of the country is enjoying a thriving job market, but buying a home is becoming more expensive," said Yun. "That is why it is an absolute necessity for there to be a large increase in new and existing homes available for sale in coming months to moderate home price growth. Otherwise, sales will remain stuck in this holding pattern and a growing share of would-be buyers — especially first-time buyers — will be left on the sidelines."