My mom became unable to work last year and she relied on me for income. She started the year with a job and Obamacare, but eventually went to Medicaid due to not being able to work. How do I specify on my tax return that only she had a plan (limited

You don't indicate if you are claiming her or if she is filing her own return as an independent.

You can't claim her if she made over $4050. When entering the Health Insurance portion, you would indicate the number of months she had insurance, whether it be Obamacare of Medicaid. If she had less than three months when she was not covered, she will get an exemption. Based on the income she did make, the program will determine whether or not she has to pay a penalty. See steps and screen shot below:

The steps of reporting are as follows:

Did you all have health insurance coverage in 2016?   We all had health insurance coverage all year. (If true)

Was anyone enrolled in any of these less common plans in 2016?  Yes

What type of plan were you enrolled in?  Obamacare plan (1095-A)

Do you have a 1095-A form to enter for your Obamacare plan?   Yes

The program will prompt you to enter the 1095-A for the months applicable.