19 Tex. Admin. Code § 22.631
Hardship and other good cause may be determined by the Board based upon documented circumstances. The Board may request assistance from the program officer at an eligible institution in determining whether or not these circumstances warrant exception to the requirement to begin fulfilling the service obligation not later than 18 months after the certification program completion date, and the requirement to fulfill the five-year service obligation within a six-year period. Such situations include, but are not limited to, a severe illness or other debilitating condition or responsibility for the care of a temporarily disabled dependent or other similar circumstances preventing the recipient from completing the five-year teaching obligation within six years after the date the person began to fulfill the teaching obligation.
19 Tex. Admin. Code § 22.631