One way to impact your 2018 tax return (and possibly taxable income) that you can do by April 15, 2019 is contribute to an HSA, or Health Savings Account, if that is available to you. Contributions to an HSA are tax deductible.  You have to have a high deductible health plan (HDHP). You can still make contributions for 2018 until April 15, 2019 and the contribution  limit is $6,900 if you have a family HDHP, if you have self only HDHP coverage, the limit is $3,450. If you are 55 years old or over, you can include an additional catch up contribution of $1,000.  You will need to complete Form 8889.