La. Stat. tit. 17 § 1222
The said boards and publicly supported educational institutions are legally authorized, enabled, and permitted to deduct from the employee's pay, salary or compensation, such parts of the premiums as are payable by the employee and as may be authorized in writing by the employee. Provided further that in the event any former employee be enjoying the benefits of any retirement plan because of former employment, such an employee shall have the right so to notify his former employer in writing of his desire to accept the benefits of said group insurance and shall according to the usual method of payment of installments as premiums pay into said institution his pro rata share of said premiums and said employer shall make the contribution as intended under R.S. 17:1221 and this Section.
La. R.S. § 17:1222