Most TCJA provisions went into effect in 2018 and apply through 2025 or are permanent, but two major changes affect individuals beginning in 2019: 1) While the TCJA reduced the medical expense deduction threshold from 10% of adjusted gross income to 7.5%, the reduction applies only to 2017 and 2018. So for 2019, the threshold returns to 10%. 2) For divorce agreements executed (or, in some cases, modified) after Dec. 31, 2018, alimony payments won’t be deductible by the payer but will be excluded from the recipient’s taxable income