First: the Foreign Earned Income Exclusion increases from $102,100 in 2017 to $103,900 for 2018. See IRS Publication 54 for more information.
Second: the 2018 business mileage rate is 54.5 cents per mile, and the 2019 rate will be 58 cents per mile.
Third: the medical expense floor was 7.5% of adjusted gross income for 2018. It is 10% of adjusted gross income for 2019.
Fourth: the contribution limit for a 401K went from $18,500 in 2018 to $19,000 for 2019. If you are 50 years of age or older, you can add another $6,000 under the catch-up rules.
Fifth: the contribution limit for an IRA goes from $5,500 for 2018 to $6,000 for 2019. If you are 50 years of age or older, you can add another $1,000 under the catch-up provisions.