There are three individuals on the Marketplace statement, how do I calculate the percentage

[wrichard14]

The Turbo Tax software says to contact Turbo Tax on how to calculate the percentage for the health care credit.

[leeloo]

If you have an individual who is on the plan but on a different tax return, you have to prorate the amounts in a manner that is acceptable to all parties. There is no one way to do this. all amounts must add up to 100%. You can take 100% on one return and 0% on the other. You can divide by thirds. You may want to play around with figures to see what ends up being the most advantageous for everyone.

[AmeliesUncle]

The answer above applies if there was Advance credit (column C of the 1095-A).  If there was NOT any Advance credit, the answer if very different.