Deductions & credits

Thank you.  My post was not clear.  I want to pay in 2021 for dental work that is currently underway but will not complete until next tax year, 2022.  I have paid a portion already in 2021.  If I pay the balance in 2021, can I take the medical deduction (as per IRS 502) in 2021?  The procedure will be complete in March 2022.  Provider is willing to accept payment in full in 2021.  Advantage is not having to meet the 7.5% threshold again next year.  

 

Thanks again.