Firstly, it's recommended that you use the Married Filing Jointly filing status.As far as claiming your children as dependents, you would claim them as stipulated in your respective divorce decree or custody agreement. In doing this, disregard the fact that you're newly married now. If this is your year to claim a child, then claim the child. If this is your new spouse's year to claim a child, then you claim the child on your joint return.
Keep in mind that even though you may not be claiming a child as a dependent, you still may be allowed to claim EIC or child care credit for that child. For tax filing purposes, having custody is not necessarily the same as it is for a divorce decree. While a divorce decree can state that one parent has custody of a child,
the requirement for the IRS generally depends on which parent the child lived with for the greater number of nights. One parent is going to live with the children more.
The non-custodial parent can never claim the Earned Income Credit or the day care credit, based on that child, even when the custodial parent has released the exemption to him.
How to claim the credits even though the ex-spouse may be claiming a child as a dependent:
Go to the Personal Info part of the program. When on the Personal Info Summary (see the screenshot below), you'll be able to edit or add a dependent from there. Answer all questions
Be sure to indicate that she lived with you at least 7 months ("I have her most of the time" rounds to 7 months). You will reach a screen where you indicate you are letting the other parent claim the child, as a dependent, this year.
