(a) Withdrawal of any form of security (indemnity bonds, negotiable securities, and/or letters of credit) is prohibited except upon express written authorization by OWCP.

(b) If a self-insurer wishes to withdraw securities, it must submit a written request, and must submit either an updated actuarial report using OWCP-mandated actuarial assumptions to support why the existing security levels are no longer applicable or replacement securities in the amount and form approved by OWCP. If OWCP approves the operator's request to withdraw and replace its securities, the operator must provide the replacement securities before it withdraws its existing securities.