I'm not sure how to calculate my premium, SLCSP, and PTC percentages. I was only on my parents health insurance marketplace (1095-A) from Jan 1 - Feb 3?

[CarolC]

You will need to use the information on the 1095-A that your parents received from the Marketplace.  You will need to talk with your parents to see how they reported the allocation percentages on their tax return.  

One option is to have your parents allocate 100%, making them responsible for the Premium Tax Credit reconciliation, and you allocate 0%.  It just makes things simpler to do it this way.  Although the allocation amount will depend on what you agree on together.  The allocation can range from 0% - 100%.

Click this TurboTax link to view Shared Allocation Examples and how to determine the percentage allocation.