(1) Compensation shall be payable for disability or death of an employee from injury or occupational disease arising out of and in the course of employment, without regard to fault as to the cause of the injury or occupational disease. An occupational disease shall be deemed to arise out of and in the course of employment when there is evidence that there is a direct causal connection between the work performed and the occupational disease. In all claims in which no benefits, including disability, death and medical benefits, have been paid, the claimant shall file medical records in support of his claim for benefits when filing a petition to controvert. If the claimant is unable to file the medical records in support of his claim for benefits at the time of filing the petition to controvert because of a limitation of time established by Section 71-3-35 or Section 71-3-53, the claimant shall file medical records in support of his claim within sixty (60) days after filing the petition to controvert.

(2) Where a preexisting physical handicap, disease, or lesion is shown by medical findings to be a material contributing factor in the results following injury, the compensation which, but for this subsection, would be payable shall be reduced by that proportion which such preexisting physical handicap, disease, or lesion contributed to the production of the results following the injury. The preexisting condition does not have to be occupationally disabling for this apportionment to apply.

(3) The following provisions shall apply to subsections (1) and (2) of this section:

(a) Apportionment shall not be applied until the claimant has reached maximum medical recovery.

(b) The employer or carrier does not have the power to determine the date of maximum medical recovery or percentage of apportionment. This must be done by the attorney-referee, subject to review by the commission as the ultimate finder of fact.

(c) After the date the claimant reaches maximum medical recovery, weekly compensation benefits and maximum recovery shall be reduced by that proportion which the preexisting physical handicap, disease, or lesion contributes to the results following injury.

(d) If maximum medical recovery has occurred before the hearing and order of the attorney-referee, credit for excess payments shall be allowed in future payments. Such allowances and method of accomplishment of the same shall be determined by the attorney-referee, subject to review by the commission. However, no actual repayment of such excess shall be made to the employer or carrier.

(4) No compensation shall be payable if the use of drugs illegally, or the use of a valid prescription medication(s) taken contrary to the prescriber’s instructions and/or contrary to label warnings, or intoxication due to the use of alcohol of the employee was the proximate cause of the injury, or if it was the willful intention of the employee to injure or kill himself or another.

(5) Every employer to whom this chapter applies shall be liable for and shall secure the payment to his employees of the compensation payable under its provisions.

(6) In the case of an employer who is a subcontractor, the contractor shall be liable for and shall secure the payment of such compensation to employees of the subcontractor, unless the subcontractor has secured such payment.