(a) No initial authorization to self-insure shall be granted for a period in excess of 18 months. A self-insurer who has made an adequate deposit of negotiable securities in compliance with §§726.106(c) and 726.107 will be reauthorized for the ensuing fiscal year without additional security if the Office finds that his experience as a self-insurer warrants such action. If the Office determines that such self-insurer's experience indicates a need for the deposit of additional security, no reauthorization shall be issued for the ensuing fiscal year until the Office receives satisfactory proof that the requisite amount of additional securities has been deposited. A self-insurer who currently has on file an indemnity bond will receive from the Office each year a bond form for execution in contemplation of reauthorization, and the submission of such bond duly executed in the amount indicated by the Office will be deemed and treated as such self-insurer's application for reauthorization for the ensuing fiscal year.

(b) In each case for which there is an approved change in the amount of security provided, a new agreement and undertaking shall be executed.

(c) Each operator authorized to self-insure under this part shall apply for reauthorization for any period during which it engages in the operation of a coal mine and for additional periods after it ceases operating a coal mine. Upon application by the operator, accompanied by proof that the security it has posted is sufficient to secure all benefits potentially payable to miners formerly employed by the operator, the Office shall issue a certification that the operator is exempt from the requirements of this part based on its prior operation of a coal mine. The provisions of subpart D of this part shall be applicable to any operator that fails to apply for reauthorization in accordance with the provisions of this section.