The code DD is the insurance cost sponsored by the employer. It is no really your cost because the amount is not taxable. In other words, you can't deduct it as your medical expense. All you have to do is report your form W-2 as it appears, no additional entries are needed on your part.
The same applies to code E - that is a retirement contribution amount that is not taxable. Since it is a pre-tax contribution, you cannot deduct it separately on your tax return. Do enter it when reporting W-2, but do not enter it anywhere else on your tax return.
