Since your son received a 1099-MISC instead of a W-2 he is considered an "independent contractor" and not an employee.
Form 1099-MISC is a catchall tax form—the "MISC" in 1099-MISC stands for miscellaneous. Income from form 1099-MISC is most commonly reported on Schedule C--the form for reporting self-employment income and expenses.
Please see this TurboTax Help article for an explanation of self-employment income as well as when you are not considered self-employed: Am I considered self-employed?
When you’re paid this way, there’s no withholding taken out of your income, which means you’ll pay both self-employment tax as well as income tax. But being self-employed enables you to have lots of write-offs as well, so make sure to enter all your expenses. This helps you reduce the taxes you might owe or increase your refund. We’ll help you get every possible tax break you deserve.
