Many tax deductions, such as charitable donations and business supplies, are well known, but some are more obscure. With tax season upon us, here’s a look at how tax deductions work and three deductions you may find surprising.
The Basics of Tax Deductions
A tax deduction is the amount you get to subtract from your income when you file your taxes. Because it reduces your income by that sum, it lowers the tax you must pay.
Individual taxpayers can claim a wide variety of deductions on their federal taxes. “The basic rules of deductions start by categorizing deductions into two buckets: Above the line and below the line,” Jake Skelhorn, a certified financial planner and partner and wealth advisor at Spark Wealth Advisors, LLC, said in an email.
He explained that above-the-line deductions such as pretax 401(k) contributions, IRA contributions and student loan interest are available whether you take the standard deduction or itemize deductions.
The IRS raised the standard deduction for 2025. It’s $15,000 for single or married filing separately, $30,000 for married filing jointly or qualifying surviving spouse, and $22,500 for head of household.
On the other hand, below-the-line deductions can be used only if you itemize deductions. You may choose to itemize your deductions if their total is greater than the standard deduction.
“Examples of common below-the-line deductions are mortgage interest, medical expenses and state and local taxes (SALT),” Skelhorn said.
As for business tax deductions, the IRS requires that business expenses are “ordinary and necessary” in your industry. They don’t have to be indispensable but must be helpful and appropriate for your line of work.
[Read: Tax Filing in 2025: How to Choose Your Filing Status]
3 Surprising Tax Deductions
With the ground rules of tax deductions in mind, here are three that may surprise you.
1. Unusual Business Assets
The IRS allows business deductions for “ordinary and necessary” costs for the industry in which your business operates. Just a few common examples are home office costs, business trips and computer equipment for your job.
However, an interesting situation arose when a professional entertainer and exotic dancer tried to depreciate her breast implants on her federal tax return. Cynthia Hess, AKA Chesty Love, said they were necessary to increase her earnings. Therefore, she and her husband claimed a $2,088 deduction in 1988 for depreciation on the surgical implants to enlarge her bust size to 56FF.
The IRS initially disallowed the request because implants are ordinarily beneficial to individuals on a personal level. The woman argued, however, that the implants were so large that they offered her no personal benefit and instead caused harm to her appearance, health and personal relationships.
The United States Tax Court ultimately sided with Hess and allowed the depreciation on the grounds that the implants offered her no personal benefit and were only useful for her business.
[Read: What’s the Difference Between a Tax Credit and a Tax Deduction?]
2. Organic Food and Salt-Free Meals
The IRS stipulates that certain costs related to nutrition, wellness, and general health are considered medical expenses. And though the agency doesn’t generally consider medically prescribed food and beverages as qualified medical expenses because they replace what you normally consume, there are exceptions.
According to the IRS, consumables can be tax deductible as a medical expense as long as certain conditions are met. The food or beverage must:
1. Not satisfy normal nutritional needs
2. Alleviate or treat an illness
3. Be substantiated by a physician as necessary
For example, a Chicago couple could only eat expensive food that wasn’t contaminated with chemicals, due to their severe allergic reactions. Three different doctors confirmed the necessity. One tax year, the couple spent $6,157 on organic food and were able to write off about half of the amount as an itemized medical expense.
In another reported case, a doctor told a man with high blood pressure and heart failure to maintain a salt-free diet. When he ate at restaurants, they charged him an additional fee to prepare meals without salt. The U.S. Tax Court decided that the additional fees he paid for salt-free meals were qualified medical expenses.
[Read: Is Organic Food Worth the Extra Cost?]
3. Dog Food, Vet Bills and Other Animal Care Costs
Per the IRS, taxpayers can include the costs involved in guide dogs and other service animals that assist a visually impaired or hearing disabled person, or a person with other physical disabilities, as a medical expense deduction.
Therefore, if you have a guide dog or service animal that’s trained to assist you or someone in your household with a disability, your related spending can qualify as deductible, below-the-line medical expenses.
And if a taxpayer with post traumatic stress disorder has a service animal that’s trained to keep them calm during an anxiety attack, the person could also write off the costs of the animal’s grooming, training, food and veterinary care.
Another deduction is available if an animal serves an ordinary and necessary role in your business. If you use a dog to guard your business premises, you can deduct the cost as a business expense.
“For example, if you own a junkyard and have a German Shepherd as a certified guard dog, you can likely deduct expenses for the dog’s care,” Adam Brewer, a tax controversy attorney based in San Diego, said in an email. However, he explained you won’t be able to do the same if you offer accounting services from a home-based office and happen to have a pet poodle.
Yet another way a pet can be tax deductible is if they perform in a way that earns you income. To illustrate, you might be eligible to deduct pet-related costs if your dog is involved in film production, your cat acts as a pet influencer or your horse takes part in competitions with cash awards.
How to Ensure Your Tax Deductions Are Allowed
Along with the above, there are a few other lesser-known deductions, Skelhorn says. These include gambling losses, casualty and theft losses, mortgage points and moving expenses. To take advantage of them you would have to meet certain conditions specified by the IRS, but if you do, they can lower your tax liability.
If you have doubts about whether a specific deduction is allowed, your best bet is to consult a certified professional.
“Consult with a tax or accounting professional about any deduction you’re not 100% sure about,” Brewer said, warning against relying on TikTok or other social media for your tax advice. “While there’s often a grain of truth to viral ‘advice,’ it’s widely misapplied. Following it could get you in trouble with the IRS.”
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These Are 3 of the Oddest Tax Deductions Ever ? Are You Eligible for One? originally appeared on usnews.com
Update 04/10/25: This story was published at an earlier date and has been updated with new information.
