Mortgage interest, charitable contributions, and medical expenses

These three deductions remain, but there have been slight tweaks made to each.

First, the mortgage interest deduction can only be taken on mortgage debt of up to $750,000, down from $1 million currently. This only applies to mortgages taken after Dec. 15, 2017; pre-existing mortgages are grandfathered in. And the interest on home equity debt can no longer be deducted at all, whereas up to $100,000 in home equity debt could be considered.
Next, the charitable contribution deduction is almost the same, but with two notable changes. First, taxpayers can deduct donations of as much as 60% of their income, up from a 50% cap. And donations made to a college in exchange for the right to purchase athletic tickets will no longer be deductible.
Finally, the threshold for the medical expenses deduction has been reduced from 10% of adjusted gross income (AGI) to 7.5% of AGI. In other words, if your adjusted gross income is $50,000, you can now deduct any unreimbursed medical expenses over $3,750, not $5,000 as set by prior tax law. Unlike most other provisions in the bill, this is retroactive to the 2017 tax year.