Personal exemption for Non-resident student paying Michigan State taxes

[dcbquicksand]

My son is a college student in Michigan but lives in Maryland.  

We claim his as a dependent on our Federal and Maryland state taxes

We do not file Michigan taxes.

Why can't he take the standard Michigan personal tax exemption in Turbo Tax ? 

[AmyC]

As a dependent, he does not claim himself but can get up to $1,500. See MI-1040 and line 9 instructions of  MI-1040 Instructions.

Take a look at his MI NR return lines 15-19 to see the exemption allowance calculation. It is MI income divided by total income to get the percentage of allowed exemption. See Schedule NR.