Box 12b code DD is the amount your employer paid for your medical insurance. You need to enter the amount you paid for medical insurance, unless your contributions are "pre-tax." (Which they often are.)
Please look at your year-end paycheck stub, which will show your deductions for such things as medical, dental, or vision insurance and Sec. 125 "cafeteria" plans, if you have one. If they are before the Federal and State tax amounts, they are "pre-tax" and you don't get to deduct them again, as you already did not pay tax on them. If they are after the Federal and State tax amounts, you will enter them in TurboTax.
