Tex. Insurance Code § 1201.219

Sec. 1201.219. POLICY PROVISION: CHANGE OF OCCUPATION. An individual accident and health insurance policy must contain the following provision if the policy addresses the subject matter of the provision:

"Change of Occupation: If the insured is injured or contracts a sickness after the insured changes the insured's occupation to one classified by the insurer as more hazardous than the occupation stated in this policy or while doing for compensation anything pertaining to an occupation so classified, the insurer will pay only the portion of the indemnity provided in this policy as the premium paid would have purchased at the rates and within the limits fixed by the insurer for the more hazardous occupation. If the insured changes the insured's occupation to one classified by the insurer as less hazardous than the occupation stated in this policy, the insurer, on receipt of proof of the change of occupation, will reduce the premium rate accordingly, and will return the excess pro rata unearned premium from the date of change of occupation or from the policy anniversary date immediately preceding the receipt of the proof, whichever date is more recent. In applying this provision, the classification of occupational risk and the premium rates are the classification and rates that, before the occurrence of the loss for which the insurer is liable or before the date of proof of change in occupation, were:

(1) last filed by the insurer with the state official having supervision of insurance in the state where the insured resided at the time this policy was issued; or

(2) if filing was not required, last made effective by the insurer in the state where the insured resided at the time this policy was issued."