(a) In determining a person's co-payment, the Texas Health and Human Services Commission (HHSC) calculates earned income each month by subtracting the following mandatory payroll deductions:(1) income tax;(2) social security tax;(3) required retirement withholding; and(4) required uniform expenses.(b) After a person or couple in an institutional setting is determined eligible, HHSC applies the payroll deductions described in subsection (a) of this section to:(1) an applicant or recipient;(2) an applicant's or recipient's spouse; and(3) a dependent relative of either spouse.