Can I claim my 18 year old son who lives at home as a dependent? His W2 was $28,000 but he doesn’t pay rent or living expenses other then his own car payment.

[DoninGA]

If he did Not provide over one-half of his own support you should be able to claim him under the Qualifying Child rules if he meets all the other rules under 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.

[xmasbaby0]

Yes--if he was only 18 at the end of 2023 he can still be claimed as your qualified child dependent.   You can get the $500 credit for other dependents for claiming him.   If he is a full-time student you will be able to claim him until the the year in which he turns 24, despite how much he earns.   If he is NOT a full-time student at 19 then your ability to claim him as a dependent will be affected by his income.

WHO CAN I CLAIM AS A DEPENDENT?

You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2023 tax return as long as they meet the following requirements:

Qualifying child

• They're related to you.
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They're under the age of 19 (or 24 for full-time students).
• No age limit for permanently and totally disabled children.
• They lived with you for more than half the year (exceptions apply).
• They didn't provide more than half of their own support for the year.

Qualifying relative

• They don't have to be related to you (despite the name).
• They aren't claimed as a dependent by someone else.
• They're a U.S. citizen, resident alien, national, or a Canadian or Mexican resident.
• They aren’t filing a joint return with their spouse.
• They lived with you the entire year (exceptions apply).
• They made less than $4,700 in 2023.
• You provided more than half of their financial support.

When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.

[piper7913n]

Thanks for the reply. 
As for providing more than half of his support, he lives full time at home, he pays no living expenses or meals at home. 
My accountant says I can’t claim him, claiming that since he made $28,000 I would have to provide evidence that I spent $28,001 (more than half) on his expenses, which makes zero sense to me. 

[rjs]

I disagree with your accountant. For a qualifying child the question is not how much he earned, it's how much he actually spent on his own support. If he put $27,000 in the bank or invested it, that is not money that he spent on support. And the value of the housing and meals that you provided is support that you paid for.

You can use the tool at the following link on the IRS web site to determine whether you can claim your son as a dependent.

Whom May I Claim as a Dependent?