Is a health insurance rider tax deductible?

I think you maybe using the wrong verbiage here? Usually the term "Health Insurance Riders refers to exclusions for Pre-existing conditions that are excluded from your policy!

Do you mean Health Insurance Premiums? Premiums are the amount you pay monthly or yearly to be insured. If you mean premiums they are tax deductible for some people, but deductions all depend on your income level, tax bracket, and several other factors that your CPA should help you with. Because what is deductible for one is not deductible for all!