The One Big Beautiful Bill Act is temporarily quadrupling the state and local tax deduction to at least $40,000, up from $10,000, for the next five years. Now it’s up to taxpayers to see if they can take advantage of this extra write-off, which is popularly referred to as the SALT deduction.

Trump-backed SALT cap increase to $40,000 offers major tax relief — but not for everyone. High earners and married filers may be left out.