(a) The department may issue a commercial learner’s permit to an individual who:
(1) has been issued a driver’s license by the department; and
(2) has passed the vision and written tests required for the class of vehicle to be driven.
(b) A commercial learner’s permit must be a separate document from a driver’s license or a commercial driver’s license.

(c) The issuance of a commercial learner’s permit is required for:
(1) the initial issuance of a commercial driver’s license; or
(2) the upgrade in classification of a commercial driver’s license that requires a skills test.
(d) A commercial learner’s permit holder may not take a commercial driver’s license skills test before the 15th day after the date of the issuance of the permit.