The Medical Expense Tax Deduction for Tax Year 2018

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Medical expenses are one of those tax deductions that have always been a bit complicated to figure out, and the rules seem to change every few years. Most taxpayers could deduct medical expenses that exceeded 10 percent of their adjusted gross incomes from 2013 through 2016. Before that, these expenses were deductible when they exceeded just 7.5 percent of a taxpayer's adjusted gross income.

Then along came the Tax Cuts and Jobs Act in January 2018.

The Effect of Tax Cuts and Jobs Act 

The threshold for deductible medical expenses was supposed to remain at 10 percent in 2016, but the TCJA tweaked that in a favorable way. It dropped the threshold back to 7.5 percent for 2017 and 2018. So you can claim the deduction for your medical expenses that exceed just 7.5 percent of your AGI on your 2018 return. 

Unfortunately, this change only applies to tax years 2017 and 2018. Beginning in January 2019, the threshold is back up to 10 percent. 

Your AGI Threshold 

You can calculate the 7.5 percent rule by tallying up all your medical expenses, then subtracting 7.5 percent of your adjusted gross income. If your AGI—which can be found on line 7 of the 2018 Form 1040—is $65,000, your threshold is $4,875 or 7.5 percent of that. If you have $10,000 in qualified medical expenses, your deduction is $5,125, or the balance over the $4,875 threshold. It's not the full $10,000

Compare this to 2016's 10-percent rule that's now back for the 2019 tax year. Your deduction would be just $3,500 or the balance over a $6,500 threshold at an AGI of $65,000. Amounts under the percent floor are not deductible.

You Must Itemize

Of course, there are multiple other rules that apply to the medical expense tax deduction as well.

First, you have to itemize your deductions to claim it, which means that you must complete and file Schedule A with your return. This could be worth your while if you're eligible to claim several other itemized deductions on Schedule A as well.

You'll want to claim the greater of your total itemized deductions or the standard deduction for your filing status. You can't claim the standard deduction and itemize, too—it's one or the other. This rule will have a much greater impact in the 2018 tax year than previously because the TCJA also nearly doubles standard deductions for all taxpayers beginning in 2018.

The standard deduction increases from $6,350 to $12,000 for single taxpayers. For head of household filers, it goes up from $9,350 to $18,000. If you're married and filing a joint return with your spouse, it jumps from $12,700 to $24,000, although if you and your spouse file separate returns, it's $12,000, just the same as if you were single.

If you don't have itemized deductions that total more than the standard deduction amounts, you'll pay taxes on more income than you have to if you don't claim the standard deduction instead.

If it does turn out that itemizing is in your best interest, medical expenses can be deducted on line 1 of Schedule A. Lines 2 and 3 of Schedule A calculate the limitation on medical expenses, and line 4 shows the deductible portion of what you paid.

Who Received Treatment?

You can deduct medical expenses paid for yourself, your spouse, and your dependents. You might also be able to deduct expenses for someone who doesn't qualify as your dependent but would have except for the following circumstances. According to the Instructions for Schedule A published by the IRS you can claim medical expenses for your dependent if:

  • You did not claim your child as a dependent because of the rules for children of divorced or separated parents.
  • You did not claim a person as a dependent on your return because that person received $4,150 or more of gross income as of 2018 or she filed a joint return.
  • You did not claim a person as a dependent on your return because that person could be claimed as a dependent on someone else's return.

Dependents of Divorced or Separated Parents

A taxpayer can deduct medical expenses for their children even if the child's other parent claims the child as a dependent. In this situation, each parent can deduct the medical expenses he paid on behalf of the child.

The parent who doesn't claim the dependent can still deduct the child's medical expenses under the special rule for children of separated parents, and the other parent can deduct the child's medical expenses they paid under the general rule that permits taxpayers to deduct medical expenses for themselves and their dependents.

Claiming Expenses for Non-dependents 

Taxpayers can also deduct medical expenses they paid for persons who would otherwise have qualified as their dependents except they earned more than the personal exemption amount for that tax year. The IRS gives the following example of this special rule:

"You provided over half of your mother's support but cannot claim her as a dependent because she received wages of at least $4,150 in 2018. You can include on line 1 any medical and dental expenses you paid in 2018 for your mother."

Pre-Tax Expenses

Only medical expenses that are not reimbursed by insurance are included in the medical expense deduction. For example, if a prescription medication costs $50 and you have a $30 copay while your insurance company pays the other $20, you can deduct only the $30 that you personally paid.

Similarly, any medical expenses paid using pre-tax dollars from a flexible spending account, a health savings account, or a health reimbursement arrangement are not included in the itemized deduction for medical expenses.

Deductions That Are Allowed 

According to Internal Revenue Code section 213(d)(1), the medical expense must satisfy one of the following conditions to be tax-deductible: 

  • Related to the diagnosis, cure, mitigation, treatment, or prevention of disease
  • Treatment that affects any structure or function of the body
  • Transportation to and from medical care
  • Long-term care services
  • Insurance for medical care or long-term care

The IRS states in Publication 502:

"Medical care expenses must be primarily to alleviate or prevent a physical or mental defect or illness...They do not include expenses that are merely beneficial to general health, such as vitamins or a vacation."

Treatments and prescriptions provided by physicians, surgeons, dentists, chiropractors, psychologists, psychiatrists, and similar medical professionals can be deducted.

Deducting Health Insurance 

Health insurance premiums count as medical expenses for purposes of the deduction, but they're subject to certain rules.

You can deduct premiums for health, dental, and vision care insurance, but only if the premiums were paid using after-tax dollars. Those who have group insurance through their employer usually pay these premiums with pre-tax dollars.

Medicare Part A premiums can be deducted if a taxpayer isn't covered under Social Security and is voluntarily enrolled in Medicare Part A. Medicare Part B premiums and Medigap premiums can be deducted. Medicare Part D prescription drug insurance premiums can be deducted as well.

Medical-Related Transportation Costs

You can deduct the cost of transportation to and from a healthcare facility if the transportation is "primarily for, and essential to, medical care," according to the IRS in Publication 502. The following expenses can be included in the cost of medical-related transportation:

  • Bus, taxi, train, or plane fares or ambulance service
  • Transportation expenses of a parent who must go with a child who needs medical care
  • Transportation expenses of a nurse or other person who can give injections, medications, or other treatment required by a patient who is traveling to get medical care and is unable to travel alone
  • Transportation expenses for regular visits to see a mentally ill dependent if these visits are recommended as a part of treatment

You can deduct the miles using the standard mileage rate for medical purposes if you travel by car: 18 cents per mile in 2018, increasing to 20 cents a mile in 2019. You can add the cost of parking and road tolls to this rate.

The Bottom Line

You can only deduct medical expenses in the year you paid them, although payment can be by cash, check, or credit card. This is the case even if medical services were provided in a different year, such as if you underwent treatment in December 2017 but paid the bill in January 2018. You would then claim the deduction on your 2018 tax return.