Maryland Commercial Law Section 15-601.1
(a)   In this section, "disposable wages" means the part of wages that remain after deduction of any amount required to be withheld by law.
(b)   The following are exempt from attachment:
(1)   Except as provided in item (2) of this subsection, the greater of:
(i)   The product of $145 multiplied by the number of weeks in which the wages due were earned; or
(ii)   75 percent of the disposable wages due;
(2)   In Caroline, Kent, Queen Anne's, and Worcester counties, for each workweek, the greater of:
(i)   75 percent of the disposable wages due; or
(ii)   30 times the federal minimum hourly wages under the Fair Labor Standards Act in effect at the time the wages are due; and
(3)   Any medical insurance payment deducted from an employee's wages by the employer.
(c)   The amount subject to attachment shall be calculated per pay period.