Fears says shortages are especially acute among lower-priced properties that appeal to first-time home buyers.
NAR figures also show extremely low inventories in parts of Texas, North Dakota (which is enjoying an oil boom) and California.
For example, Greater Los Angeles has just a 3.8-month supply of available homes -- roughly half the 6.5- to seven-month inventory Realtors consider sufficient to meet demand.
L.A.'s available listings are also a far cry from the 19.9-month backlog that the California Association of Realtors says the area saw in September 2007 during the depths of the bust.In Ventura, Heyrend says house-hunters often find themselves in bidding wars even when they offer more than a home's list price. But the shortage is great news for sellers, reducing the time it takes to move their homes even as property values rise. Ventura County's median house price hit $461,960 last month -- a 17.7% gain from February 2012 -- and Heyrend says any realistically priced house listed for $400,000 or less will sell within two weeks. That said, Fears believes today's shortages will end in two years or less as rising prices cut investor demand and many underwater homeowners manage to get "above water" and sell. He also says builders only need around 18 months to bring new supply to the market. Heyrend expects the market to balance out even more quickly in her town, with more homeowners listing properties this summer as they hear about rising prices. "I think sellers will eventually say: 'Man, I can finally make some money on my home,'" she says.