For a worker making $40,000 or less, standard deductions often already wipe out federal tax obligations. But for someone in the $50,000 to $100,000 range, shielding $12,500 in overtime or $25,000 in tips could move them into a lower tax bracket.

The changes won’t happen all at once. Here’s when Americans can expect key provisions of the GOP tax and spending bill to go into effect.