On the question, how many months did my child live w me. if my ex husband gets him 50 percent of the time. how should i answer.?? is it fine to put whole year?

[ReginaM]

No, you can not list your child lived with you for the whole year when he lived with you only part of the year.  

As far as the IRS is concerned, there is no 50/50 split for a child. One parent has to be the custodial parent and one has to be the non-custodial parent.

Custodial parent and noncustodial parent.   The custodial parent is the parent with whom the child lived for the greater number of nights during the year. The other parent is the noncustodial parent.

  If the parents divorced or separated during the year and the child lived with both parents before the separation, the custodial parent is the one with whom the child lived for the greater number of nights during the rest of the year.

  A child is treated as living with a parent for a night if the child sleeps:

• At that parent's home, whether or not the parent is present, or
• In the company of the parent, when the child doesn't sleep at a parent's home (for example, the parent and child are on vacation together).

Equal number of nights.   If the child lived with each parent for an equal number of nights during the year, the custodial parent is the parent with the higher adjusted gross income (AGI).

See IRS Publication 504 for more information.

[Opus 17]

For Federal Tax Law, the important question is, "which parent did the child live more than half the nights of the year"? It can't be 50/50 in a year with an odd number of days, and the IRS does not follow custody orders, only where the child actually spent the night.  The nights do not have to be consecutive.  

Turbotax deals with this question by asking you to estimate how many months the child lived with you.  For example, if the child lived 2 nights a week with one parent and 5 nights a week with the other parent, the parents might approximate by picking "3 months" and "9 months" in the interview.

As long as your child lived with you more than half the nights, it doesn't matter if you choose 7, 8, 9, 10, 11 months or the whole year in the program.  All are treated as "more than half".   Likewise, if the child spent the night in your home less than half the nights of the year, it doesn't matter if you choose 1, 2, 3, 4, 5, 6 months or never.  All are treated for tax purposes as "less than half."