It is possible he can be claimed as a dependent only if you file a separate return and in the year of 2016 he:
-had no gross income,
-isn't filing a return,
and
-wasn't the dependent of
another taxpayer.
If you were married and filed jointly, you
cannot claim him as a dependent, as each spouse gets a personal
exemption on a married filing jointly tax return which is equal to a dependency
exemption.
