Colorado Revised Statutes Title 8. Labor and Industry § 8-44-114. Determination of premium

The amount of the premium to be paid by an employer for a contract of insurance of compensation and benefits as provided in articles 40 to 47 of this title or against liability therefor shall be on the basis of the annual expenditure of money by said employer for the services of persons engaged in such employer's employment; except that no portion of such expenditure representing a per diem payment shall be considered unless such payment is considered wages for federal income tax purposes.