40 Pa. Stat. § 918
A mutual insurance company, other than a mutual life company, not possessed of assets at least equal to the unearned premium reserve and other liabilities, shall make an assessment upon its members liable to assessment to provide for such deficiency. Such assessment shall be against each member in proportion to such liability as expressed in his policy. No member shall be assessed for any loss that occurred when his policy was not in effect and no assessment shall be made after two years from the expiration or cancellation date of a policy and no such assessment shall be made without the prior written approval of the Insurance Commissioner. For each year the policy is in force, such assessment shall be an amount not greater than the annual or the average yearly cost or premium of the policy for the period it has been in effect. Such assessment shall not exceed two times the average yearly cost or premium of the policy for the period it has been in effect. The Insurance Commissioner may, by written order, relieve the company from an assessment or other proceedings to restore such assets during the time fixed in such order. Any domestic company which shall be deficient in providing the unearned premium reserve required hereby may, notwithstanding such deficiency, come under this act on the condition that it shall each year thereafter reduce such deficiency at least fifteen per centum (15%) of the original amount thereof, and in such case it may increase its assessments accordingly.
The provisions of this section are not applicable to assessments made upon the members of a company by the Insurance Commissioner pursuant to the authority granted him by Article V, act of May 17, 1921 (P.L. 789, No. 285), known as "The Insurance Department Act of one thousand nine hundred and twenty-one."
40 P.S. § 918