One of my dependents went to junior college for the first semester and them he stops and started to work for 3 months, after that he was let go and he hasn't work since.

It depends on your dependents age and how much money they made, along with other requirements. To determine if you can claim him as your qualifying child, the following questions must be true.

 

For a Qualifying Child Dependent:

• He must be related to you. 
• He can’t be claimed as a dependent by someone else. 
• He must be a U.S. citizen, resident alien, national, or a Canadian or Mexican resident. 
• If he's married, he can’t file a joint return with his spouse. 
• He must be under the age of 19 (or 24 for full-time students). 
  • No age limit for permanently and totally disabled children. 
• He must have lived with you for more than half the year (exceptions apply). 
• He didn't provide more than half of his own support for the year. 

If your dependent doesn't meet the eligibility requirements for a qualifying child dependent, he may meet the requirements of a qualifying relative dependent:

 

For a Qualifying Relative Dependent:

• His income must be less than $4,700
• You provided over half of his support
• He's not filing a joint tax return if married unless filing to claim a refund of withholding
• He Must be a U.S, citizen, U.S. resident, U.S. national or resident of Canada and Mexico
• He must live with you all year, unless he falls under one of the categories—Does a dependent for 2023 have to live with me?

For additional information, review the TurboTax article Rules for Claiming a Dependent on Your Tax Return.

 

If you do claim your son as your dependent and he files his own tax return, make sure that he indicates that someone else is claiming him as a dependent.  Refer to the TurboTax article: How do I indicate that I can be claimed as a dependent on someone else's return?

 

If he doesn't qualify as your dependent, review the IRS website Fact Sheet Who needs to file a tax return to determine if he needs to file a federal tax return.