My son turned 18 this year and was claimed by his other parent in years past what happens now that he is 18 and lives with me? Who gets to claim him

[DoninGA]

If he lived in your home in 2019 for more than one-half of the year, you are the custodial parent and can claim him as a dependent under the Qualifying Child rules if he meets all the requirements.

To be a Qualifying Child -

1. The child must be your son, daughter, stepchild, foster child, brother, sister, half brother, half sister, stepbrother, stepsister, or a descendant of any of them.
2. The child must be (a) under age 19 at the end of the year, (b) under age 24 at the end of the year and a full-time student or (c) any age and permanently and totally disabled.
3. The child must have lived with you for more than half of the year. Temporary absences while away at college are considered living with you.
4. The child must not have provided more than half of his or her own support for the year.
5. If the child meets the rules to be a qualifying child of more than one person, you must be the person entitled to claim the child as a qualifying child.
6. The child must be a U.S. citizen or U.S., Canada or Mexico resident for some portion of the year.
7. The child must be younger than you unless disabled.

[Opus 17]

Assuming your child is emancipated at age 18 in your state (most states, a couple are younger or older), then the "special rules for children of divorced and separated parents" no longer apply, and you go back to the basic rules that apply to anyone else.  

You can claim your child as a dependent if he lives in your home more than half the year (including temporary absences) and does not support himself.  (There are a few other tests but that's the basics.)

Your ex can't claim the child as a dependent using a pre-2009 divorce agreement or with form 8332.  If you have a divorce agreement that requires you to give your ex a signed form 8332 even though your child is 18, you may need to get your attorney or a tax specialist to explain to your ex that those rules stop applying when the child is legally emancipated under state law.  

(If your ex has been claiming the child all along without you giving your ex a signed form 8332, then you both have been doing it wrong -- you may have been cheating yourself out of significant tax benefits and your ex may have received benefits they were not entitled to.)

[mason_11_11_02]

Thanks.  I live in Ohio.  We were never married and he has always lived with me the entire year.  My son turned 18 in November so I wasn’t sure how it worked since I received child support up u til his 18th birthday but obviously that has stopped.  

[macuser_22]

Then the 8332 and 6 month custody rule probably still apply because he lived with you for more then the required 6 month period before turning 18.    The rules for the 8332 deal with custody and custody ends when emancipated.

However, it makes no difference unless there is a court order or agreement that allows the other (non-custodial) parent to claim the dependent until emancipated .   If no such order or binding agreement,  then you can claim if the child lived with you.

See IRS Pub 17, Emancipated child, examples 5 & 6 on page 28.

Example 5—Child emancipated in May. When your son turned age 18 in May 2020, he became emancipated under the law of the state where he lives. As a result, he isn't considered in the custody of his parents for more than half of the year. The special rule for children of divorced or separated parents doesn't apply.

Example 6—Child emancipated in Au-gust. Your daughter lives with you from January 1, 2020, until May 31, 2020, and lives with her other parent, your ex-spouse, from June 1, 2020, through the end of the year. She turns 18 and is emancipated under state law on August 1, 2020. Because she is treated as not living with either parent beginning on August 1, she is treated as living with you the greater number of nights in 2020. You are the custodial parent.

https://www.irs.gov/pub/irs-pdf/p17.pdf