5 C.F.R. § 9701.707
(b) Procedures.
(5) The decision of the Department must be sustained if it is supported by a preponderance of the evidence, unless the employee shows by a preponderance of the evidence—
(6)
(c) MSPB review.
(1) In order to obtain judicial review of an MRP decision, an employee, the Department, or OPM must request a review of the record of an MRP decision by MSPB by filing such a request in writing within 15 days after the issuance of the decision. Within 15 days after MSPB's receipt of the request for a review of the record, any response or OPM intervention must be filed. A party, or OPM, may each submit, and MSPB may grant for good cause shown, a request for a single extension of time not to exceed a maximum of 15 additional days. MSPB will establish, in conjunction with the MRP, standards for the sufficiency of the record and other procedures, including notice to the parties and OPM. MSPB must accept the findings of fact and interpretations of this part made by the MRP and sustain the MRP's decision unless the employee shows that the MRP's decision was—
(2) MSPB must complete its review of the record and issue a final decision within 30 days after receiving the party's timely response to such request for review or OPM's intervention brief, whichever is filed later. This 30-day time limit is mandatory, except that MSPB may extend its time for review by a maximum of 15 additional days if it determines that—
(d) Subsequent action.
(1) If either the MRP or MSPB sustains an employee's appeal based on a finding that the employee did not commit an MRO, the Department is not precluded from subsequently proposing an adverse action (other than an MRO) based on the same record evidence. Such a proposal must be issued—
(f) OPM intervention.