Regarding Market Based Health Insurance, as the parent, do i check the box that asks if I shared the plan with another taxpayer? My son was recommended not to by you.

[just-ask]

My wife and I share the health plan with my son. Son files his own taxes and is not a dependent.  TurboTax recommends he doesn't check the share box, but do my wife and I check the shared box?  We live in Washington.  If we do share, then I calculated our percentage is 80%, but what do we put in the three boxes that ask for the percentages?

[MonikaK1]

For the months that your son was on your policy, you can allocate the amounts in any way you both agree.  This means you can allocate 100% to yourself, or you can split it anyway you choose. If you both agree, the allocation can be anywhere from 0% to 100%.  

If you cannot agree, and Advance credit was received (column C on the 1095-A), then it is divided by the number of people on the insurance policy.  For example, if the insurance policy covers 4 people, each person is allocated 25%.

See this TurboTax tips article for more information about Form 1095-A.

See also this IRS article for more information about the Premium Tax Credit.