One of the most cherished tax breaks in America, deducting the interest on a home mortgage, is going to get whacked down to size in the next few years.

Fortunately most Americans won’t really notice.

A group of congressional tax experts predict claims for mortgage deductions will fall 30% in 2018 — to $40.7 billion from $66.4 billion in the year before the Trump tax cuts took effect. Claims will decline even further to $34 billion in 2019.

Also Read: Existing-home sales tumble as supply crunch squeezes

The estimate is included in an updated assessment of the tax law by the Joint Committee on Taxation, a congressional panel that includes members from the House and Senate.

The law championed by President Trump and Republicans included a sharp reduction in how mortgage debt would qualify for an federal interest-rate deduction. The provision was added to help pay for the tax cuts.

Also Read: Mortgage rates march to fresh 7-year high

Home owners will now only be able to deduct interest on $750,000 worth of mortgage debt instead of $1 million under the old rules.

Also Read: Home prices will fall 10% if state, local deduction taken away, Democrats say

By and large, most households won’t notice a big difference. The average cost of a previously owned home is about $258,000, according to the National Association of Realtors. (New houses cost more). And many homeowners didn’t itemize anyway.

The new law also aims to encourage taxpayers to forego the mortgage deduction entirely for cheaper homes by doubling the size of the standard deduction.

The change to the mortgage deduction will mostly hit high-income earners with expensive homes in urban areas, especially big cities such as New York and Los Angeles.

Now read:Watch for these pitfalls if you want to deduct mortgage interest under the new tax law