The linked TurboTax article will provide most of what you need to know to file a final return for your son.
https://turbotax.intuit.com/tax-tips/family/death-in-the-family/L5albFXM4
Within the TurboTax product, the steps are fairly simple. In Personal Information, be sure to enter the date of death. Complete Form 1310, Statement of Person Claiming Refund Due a Deceased Taxpayer and file with the Form 1040. Include all income and deductions through the date of death.
Finally, I realize
that your inquiry means that you have experienced a loss no parent should ever have to bear. For
myself, and on behalf of our entire team at Intuit, Inc., please accept our
sincere condolences.
