I paid for my son braces which wasn't covered by insurance. Is that tax deductible?

[Critter-3]

That is a medical expense that you can put on the Sch A  if you itemize deductions. 

[Texas Roger]

As Critter-3 says, this would be an itemized deduction. Only the amount of medical expenses in excess of 7.5% of your AGI can be deducted. All of the itemized deductions must total more than the standard deduction for you to get a tax benefit.

See this if you need to learn more about standard vs. itemized deductions: https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-credits-deductions/standard-deductio...