A desk with someone filling out their itemized deductions

About 30 percent of all households itemize their taxes, but that percentage could soon drop dramatically.

The new Tax Cuts and Jobs Act, passed last year, made itemizing less beneficial for millions of Americans: It doubles the standard deduction and eliminates write-offs for numerous expenses.

As a result, around only 11 percent of taxpayers are expected to itemize their federal returns next tax season, according to the Washington-based Tax Policy Center

But for this tax season, you can still write off a cornucopia of items, from gambling losses to unreimbursed employee expenses. Here are the rules for some common itemized deductions.

Charitable Donations

• Do keep good records. The IRS requires receipts for all deductible donations. All charitable deductions, no matter how small, must be substantiated either by a canceled check; bank record containing the charity’s name, donation amount, and date; or a detailed receipt from the charity. Otherwise the contribution cannot be an itemized deduction. 

• Do collect your charitable acknowledgments, receipts, and canceled checks in one place. If you make cash donations, you'll need either a bank statement or a written communication from the charity noting the charity name, your donation amount, and the date. For more, check IRS Publication 526, "Charitable Contributions."

• Don't claim donations of furniture, clothing, and other household goods that weren't in at least good condition when you gave them. While the IRS rule aims to weed out junk donations, taxpayers may claim an itemized deduction of more than $500 for any single item in any condition as long as a qualified appraisal is included with their return.

Medical Expenses

• Do deduct premiums for the Medicare Part D prescription drug insurance program, as well as other health insurance premiums you pay yourself. The premiums for long-term-care insurance are deductible on a sliding scale according to your age.

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• Do deduct gas mileage expenses for your car when used for medical reasons. The 2017 rate for such deductions was 17 cents per mile for medical travel.

• Do read the IRS list of deductible medical and dental expenses in IRS Publication 502, "Medical and Dental Expenses." The following costs, for example, are deductible to the extent that they address a health problem: wigs recommended by a doctor for the mental health of a patient suffering hair loss due to disease, special mattresses and bed boards, back supports, elastic hosiery, childbirth classes (fees for the mother only), and remedial reading instruction for dyslexic children.

• Don't expect much. For 2017 and 2018 you can deduct only unreimbursed medical and dental expenses that exceed 7.5 percent of your adjusted gross income. But if you're self-employed, your health insurance premiums may be 100 percent deductible. See Publication 502 for eligibility criteria.

Retirement Accounts

• Do contribute to an IRA if you're eligible. You have until the April 17 filing deadline to make a contribution.

Taxpayers younger than 50 can still put in up to $5,500 for 2017; those 50 and older can sock away $6,500. For 2017, if you're single and covered by a retirement plan at work, your deduction for contributions to a traditional IRA will be phased out if your adjusted gross income is more than $62,000 but less than $72,000; the limits are $99,000 but less than $119,000 for joint filers. (After those upper limits, you get no deduction.) 

IRA contributions for spouses must be figured individually, even if the couple files jointly. The IRA contribution of the lower-earning spouse may be affected by how much the other spouse earned and contributed to an IRA. See IRS Publication 590A, “Contributions to Individual Retirement Arrangements IRAs,” for more information.

• Do fund a SEP IRA if you made money from self-employment last year.