I believe you mean you had a reduction in your insurance premiums because you had health insurance through the government exchange, Obamacare or something similar.
If so, the insurance company will send you a form 1095-A that you can use to enter your premium tax credit information into Turbotax.
You do this as follows:
If you received a form 1095-A, you can enter that in the "Deductions and Credits" section, then "Medical", and then "Affordable Care Act (Form 1095-A)." You will be prompted to enter the information off of your form 1095-A. You will be asked if you shared the policy with someone who is not on your tax return. If not, then you just need to enter the information from your 1095-A form and you will be done.