WASHINGTON, DC—Existing-home sales and price growth in the single-family sector, including for-sale apartments, are expected to slow in the coming year, the National Association of Realtors said Wednesday. The forecast of a slowdown is due mainly to homeowners' diminished ability to claim deductions under the tax reform bill signed into law last week by President Trump.

By the numbers, NAR expects existing-home sales to finish 2017 at around 5.54 million, up 1.7% from the year prior. The national median existing-home price this year is expected to increase around 6% year over year. For 2018, though, the association expects a slight decline—0.4%—to 5.52 million, and Y-O-Y price growth to moderate to around 2%.

Even so, NAR's forecast calls for sunshine mixed in with the clouds. “The strengthening economy, and expectation that more Millennials will want to buy, serve as promising signs for solid homebuying demand next year, while also putting additional pressure on inventory levels and affordability,” says Lawrence Yun, the association's chief economist. “Sales do have room for growth in most areas, but nationally, overall activity could be slightly negative. Markets with high home prices and property taxes will likely feel some impact from the reduced tax benefits of owning a home.”