Yes, you can click here for instructions on how to Amend Your Return to get the penalty you paid for not having insurance back.

However, if this insurance was Obamacare and you already filed, the IRS will be contacting you asking you for an 8962.  If this is your situation, do not file an amended return.  Wait for the IRS to contact you and then take the following steps to generate the 8962 to send back to them. They will take care of the rest. 

You will need to log back into your return and then click Add a state in order to get back into your return. Once Fully logged in do the following

• Click Federal
• Click Health Insurance
• Select You had insurance all year or  I'll pick and choose which months
• Click Continue
• If applicable, select the Months you had insurance and click continue
• Continue through until you get to "Was anyone covered by any of these plans in 2018?"
• Answer yes and you will be prompted to enter your 1095-A

You can then go to the print center and print just the 8962