If you were covered all 12 months, you will enter on the initial healthcare screen that you had health insurance coverage all year. If you didn't have coverage all year, select I had it for part of 2016.

Next you will indicate that you had a Marketplace plan for part of the year. You should receive a Form 1095 A for the time you had California Marketplace insurance.

You only need to enter information for any period of time where you had Obamacare or Marketplace insurance.  You will enter the information from Form 1095 A for this insurance.  You should enter the information only for the months you were covered by an Obamacare or Marketplace insurance policy.
 
For insurance offered through your employer, you will only enter that you were covered by insurance. No other information is necessary.