The Feb 2018 budget deal brought appears to have brought back this deduction (max $500) retroactively for 2017. See

 <a rel="nofollow" target="_blank" href="https://www.forbes.com/sites/ashleaebeling/2018/02/09/budget-deal-revives-expired-individual-tax-bre...>

and

<a rel="nofollow" target="_blank" href="https://email.steptoecommunications.com/22/1412/uploads/summary-of-tax-extenders-agreement.pdf">http...>
(search for "Section 40401")

<a rel="nofollow" target="_blank" href="https://www.irs.gov/newsroom/irs-statement-on-retroactive-extender-provisions">https://www.irs.gov/n...>

FYI ... it could take the IRS and the tax software companies 3 weeks or more to get those forms updated and operational.