Generally, the right to claim the child as a tax dependent is addressed in the Separation Agreement between the parties.
Even if you were not married, it still is a good idea to enter into a Separation Agreement , which would spell out exactly the relationship and the obligations of each of the parties.
In many cases like yours, the parties agree to share the right to claim the child as a dependent by alternating the years, and this can be done by both of you filling out IRS tax form 8332 and indicating that one will be taking the deduction in the even years , and the other will be taking it in the odd years.
If you are living in the New York City metropolitan area , and wish to discuss entering into a written Separation Agreement, please call me at 212-370-1660.
Leonard M. Weiner, Esq./Divorce Solutions