How the IRS Defines Medical Care and Medical Necessity

The IRS defines medical care, under Section 213(d) of the Internal Revenue Code, as amounts paid for the diagnosis, cure, mitigation, treatment, or prevention of disease, or for the purpose of affecting any structure or function of the body.¹ That single definition decides whether an expense qualifies for the itemized medical deduction on Schedule A, whether you can pay for it tax-free from a Health Savings Account, and whether an FSA or HRA can reimburse it.

The definition has two prongs, and they work differently. The first covers spending aimed at a specific illness or condition. The second is broader: it captures expenses that don’t target a disease but genuinely change how the body works, such as orthodontics to correct jaw alignment or fertility treatments to address an inability to conceive. What ties both prongs together is intent. The expense has to be primarily therapeutic, not personal. A relaxing vacation your doctor suggested does not qualify; a treatment that addresses a diagnosed condition does. That distinction runs through every IRS ruling and publication on medical expenses.

Where the Definition Actually Matters

Section 213(d) feeds three separate tax benefits, and knowing which one you are using changes what you have to prove and what you save.

On Schedule A, you can deduct qualifying medical expenses to the extent they exceed 7.5% of your adjusted gross income, and only if you itemize.¹ If your AGI is $80,000, only medical expenses above $6,000 count toward the deduction.

Health Savings Accounts use the exact same Section 213(d) definition to identify “qualified medical expenses.”² Distributions for qualifying costs are tax-free, and there is no AGI floor to clear.³ Use HSA funds for something that does not qualify and you owe income tax on the distribution plus a 20% penalty if you are under 65.

FSAs and HRAs also build on the Section 213(d) definition, though your employer’s plan document can narrow what is covered. FSA balances generally need to be spent within the plan year or a short grace period, while HSA funds roll forward without expiration.

Expenses the IRS Accepts Without Argument

Some expenses fit the definition so cleanly that a standard receipt is enough. Services from physicians, surgeons, dentists, and other licensed practitioners qualify. Hospital stays for medical treatment qualify. Diagnostic tests, blood work, and imaging qualify. Dental care from cleanings to oral surgery qualifies, and vision care including eye exams and corrective lenses qualifies.⁴ Prescription drugs are recognized without question because their entire purpose is treating a health condition.

Mental health care sits in the same clear-cut category. Psychiatric care, psychologist visits, and psychoanalysis all qualify, as do inpatient treatment programs for drug or alcohol addiction, including meals and lodging at the treatment center. Legal fees paid to authorize treatment for a mental illness count as well. The IRS draws no practical line between physical and mental health here.⁴

Fertility treatments to overcome an inability to have children qualify, including in vitro fertilization, temporary storage of eggs or sperm, and surgery to reverse a prior sterilization. Fees paid for a gestational surrogate’s identification, compensation, or medical care do not qualify, because the surrogate is not you, your spouse, or your dependent.⁴

Guide dogs and other service animals that assist with a visual, hearing, or physical disability also qualify, along with the ongoing costs of food, grooming, and veterinary care that keep the animal working.⁴

Over-the-Counter Products Follow a Split Rule

The same bottle of ibuprofen gets two different answers depending on which tax benefit you are using.

For the Schedule A itemized deduction, OTC drugs that do not require a prescription generally cannot be included as medical expenses. Insulin is the exception; it qualifies whether or not it is prescribed.⁴

For HSAs, FSAs, and HRAs, the CARES Act removed the prescription requirement in 2020. You can now use these accounts to pay for OTC medicines and drugs without a prescription, and menstrual care products such as tampons, pads, liners, and cups are reimbursable as well.⁵ Menstrual care products are treated as qualified medical expenses for HSA purposes by statute.²

Practically: if you are paying out of pocket and plan to itemize, OTC drugs will not help your deduction. If you are paying from an HSA or FSA, they are fair game.

When You Have to Prove Medical Necessity

Plenty of expenses could serve either a medical or a personal purpose. Weight loss programs, gym memberships, nutritional supplements, special education, and home modifications all sit in this gray zone. For these, you have to show that the expense was primarily aimed at treating a specific diagnosed condition rather than improving general health.

The standard tool is a Letter of Medical Necessity from your treating physician. It should identify the patient, state the specific diagnosis, explain why the expense is medically required, and indicate the expected duration of treatment. A vague note that exercise “would be beneficial” is not enough; the letter has to tie a specific expense to a specific condition.⁶

When the IRS evaluates a borderline expense, it looks at why you incurred the cost, whether a physician diagnosed a condition and recommended the treatment, how directly the treatment relates to the illness, and how close in time the expense was to the onset or recurrence of the condition.⁶ An incidental health benefit is not enough; the expense has to bear a direct relation to the condition being treated.

Weight Loss, Gyms, and Supplements

The belief that gym memberships and weight loss programs are never deductible is wrong. A weight loss program qualifies if it treats a disease diagnosed by a physician, such as obesity, diabetes, hypertension, or heart disease. A gym membership qualifies if it was purchased for the sole purpose of treating a diagnosed condition or affecting a structure or function of the body, such as a prescribed physical therapy plan for an injury.⁷

Nutritional supplements work the same way. A multivitamin for general wellness does not qualify. The same supplement recommended by a medical practitioner to treat a specific diagnosed condition does.⁷ The line is always general wellness versus a specific physician-diagnosed disease.

Special Education

Tuition at a school that provides special education to help a child overcome learning disabilities can qualify, but only if overcoming the disability is the primary reason for attending and any regular education received is incidental to the special instruction. Fees for tutoring by a teacher specially trained to work with children who have learning disabilities caused by physical or mental impairments also qualify when recommended by a doctor.⁴ A school chosen mainly for disciplinary structure does not qualify, even if the child benefits.

Home Improvements

Installing a wheelchair ramp, widening doorways, adding bathroom handrails, or lowering kitchen counters can qualify when done for a diagnosed disability. Improvements that do not increase the home’s market value can be included in full as medical expenses.⁴

For improvements that do add property value, only the difference counts. Spend $15,000 on an accessible bathroom that raises your home’s value by $10,000 and the deductible medical expense is $5,000. Ongoing costs of operating and maintaining a medically necessary improvement remain fully deductible as medical expenses even if the original installation cost only partially qualified, so long as the main reason for the expense stays medical.⁴

Cosmetic Surgery

Cosmetic procedures aimed at improving appearance generally do not qualify. Facelifts, hair transplants, and liposuction that do not treat a disease or correct a functional problem fall outside the definition.⁴ The exception is important: cosmetic surgery does qualify when it corrects a deformity arising from a congenital abnormality, a personal injury from an accident or trauma, or a disfiguring disease.⁸ Reconstructive surgery after a mastectomy, scar revision after a car accident, and correction of a cleft palate all fall on the deductible side. The expense still has to address the deformity itself.

Travel to Get Care

Transportation to and from medical appointments qualifies. For 2026, the standard mileage rate for medical travel is 20.5 cents per mile.⁹ Tolls, parking, and fares for buses, taxis, trains, and ambulances all count.

When treatment requires an overnight stay away from home, lodging qualifies up to $50 per night per person. If a parent travels with a sick child, both lodging amounts can be included, capped at $100 per night combined. The lodging cannot be lavish, and the trip cannot involve any significant element of personal pleasure or recreation.⁴

Long-Term Care and Nursing Homes

Nursing home expenses qualify as medical care if the primary reason for being in the facility is to receive medical or nursing treatment; when that is the case, the full cost including meals and lodging counts. If the primary reason is personal, only the portion attributable to actual medical or nursing care qualifies.⁴

Qualified long-term care insurance premiums are deductible as medical expenses, but only up to age-based per-person limits. For 2026:

Age 40 or younger: $500
Ages 41 to 50: $930
Ages 51 to 60: $1,860
Ages 61 to 70: $4,960
Age 71 and older: $6,200

Any premium amount above the limit for the person’s age bracket is treated as a personal expense. For long-term care benefits to be tax-favored, the individual must be “chronically ill,” which federal law defines as being unable to perform at least two activities of daily living (eating, bathing, dressing, toileting, transferring, or continence) for at least 90 days due to loss of functional capacity, or requiring substantial supervision due to severe cognitive impairment. A licensed health care practitioner must certify the condition.¹⁰

What Happens if a Claim Does Not Hold Up

If the IRS decides that an expense you claimed does not meet the Section 213(d) definition, the deduction is disallowed, and you owe the tax you should have paid plus interest from the due date. When the underpayment stems from negligence or careless disregard of the rules, the IRS can add a 20% accuracy-related penalty on top of the tax.¹¹

The same risk applies to HSA distributions. Funds used for something that does not qualify are included in taxable income and hit with an additional 20% tax if you are under 65. Documentation is the protection worth building in advance: keep receipts for medical expenses, get a Letter of Medical Necessity before incurring any dual-purpose cost, and hold the records for at least three years after filing the return that claimed the expense.

1
Office of the Law Revision Counsel. 26 USC 213 – Medical, Dental, Etc., Expenses
2
Office of the Law Revision Counsel. 26 U.S. Code 223 – Health Savings Accounts
3
Internal Revenue Service. Publication 969 – Health Savings Accounts and Other Tax-Favored Health Plans
4
Internal Revenue Service. Publication 502 – Medical and Dental Expenses
5
Internal Revenue Service. IRS Outlines Changes to Health Care Spending Available Under CARES Act
6
Internal Revenue Service. IRS Office of Chief Counsel Memorandum 2019-0005
7
Internal Revenue Service. Frequently Asked Questions About Medical Expenses Related to Nutrition, Wellness, and General Health
8
Office of the Law Revision Counsel. 26 U.S. Code 213 – Medical, Dental, Etc., Expenses
9
Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents per Mile, Up 2.5 Cents
10
Legal Information Institute. 26 U.S. Code 7702B – Treatment of Qualified Long-Term Care Insurance
11
Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments