What medical costs are deductible
The over-arching concept is the incremental cost required to become well from an unwell state. We can deduct the seeing eye dog's dog food and the chinese herbs prescribed to fix an illness. (There is no tie-in to western medicine in the code.) We cannot deduct vitamins designed to STAY well from a well state.
An exception I've never seen examined is that we can deduct well-baby visits and/or annual physicals. I don't know why.
We can deduct any method of weight loss other than eating less and exercising more, i.e., health clubs are statutorily prohibited (it's the same organizational structure as yacht clubs and golf clubs...) and we cannot deduct the incremental cost of eating GOOD food versus crappy food.
Celiacs keep attempting to deduct the higher cost of wheat-free pasta or whatever, but it falls flat because it's actually CHEAPER and HEALTHIER to eat a wheat-free diet. Think about it: you just eat rice and vegetables and unadulterated foods. Instead of "gluten-free beer" you drink water. D'oh! Not deductible.
Add'l education costs of children with learning disabilities has NOT stood up in court cases to my knowledge. I'd love a cite on that. I've not been deducting all the tutoring costs of kids who need help passing AP calc, for example.
Also, medical costs that are deductible only become useful on your tax return to the extent that they become extraordinary in amount. Helpfully, the IRS defines what "extraordinary amount" is: more than 7.5% of your adjusted gross income. Under that and it's just the cost of having a human body. So if your income is $100,000 then you cannot deduct the first $7,500 in medical expenses.
And even the amount above that may be useless to you because you may still be better off with the standard deduction OR because you may already have a Federal income tax bracket of 0%. A shocking amount of people are paying NOTHING in Federal taxes. Zero. Zilch. They may be paying Self-Employment tax, they may be paying penalties, but medical deductions do not create a refundable tax credit in any way. Nor do they carryforward.
Last comment: people come to me and talk about their expensive gluten-free pizza but forget to add up what they're paying out of pocket for health INSURANCE. If you're writing a check for $450 every month for health insurance you probably want to mention it somewhere before you try for 16.5 cents a mile for your therapy visits. Also, dental insurance and long-term care insurance are deductible if paid out of pocket in after-tax dollars. (Amounts paid through payroll at work are already in pre-tax dollars.)
Oh, and life insurance and disability insurance payments are not deductible. Consequently, life insurance and disability insurance PAYOUTS are not taxable income.