What if I'm on my mom health insurance.

If you are being claimed as a dependent on your moms return, then you do not need to enter any health insurance information.  Just be sure you mark that you are claimed as a dependent in the personal info section. 

If you are not being claimed, you will need to enter her 1095-A on your return. After the form is entered you will be asked if this was a shared policy, if it was you will click yes.  Then you will be able to allocate an amount to you and your mom.  You can claim 100% or 0%, she can do the same as long as it adds up to 100%. Many times parents paid the premiums and will allocate the full amount to themselves, while the kids just enter the form and allocate 0%.