On Monday, EPA filed a status report in the CPP litigation informing the court that it “has begun the interagency review process of a proposed regulatory action resulting from its review of the” Clean Power Plan. The status report comes in the midst of the court-ordered 60-day abeyance period, and the court’s pending consideration of whether to remand the rule back to EPA or continue the abeyance period.
In its abeyance order, the Court had directed EPA to file status reports on 30-day intervals. The first status report, filed on May 30, 2017, stated that EPA was continuing to review the Rule and “may be prepared to begin the interagency review process of a resulting proposed regulatory action in the near future.” The latest status report (which was unscheduled) informs the court that EPA has sent a draft proposed rule to the Office of Management and Budget (OMB) for its review. The status of the proposed rule, entitled “Review of the Clean Power Plan” can be found here (RIN 2060-AT55).
The requirement that OMB’s Office of Information and Regulatory Affairs review proposed regulations comes from Executive Order 12,866 (as supplemented by Executive Order 13,563). Executive Order 12866 directs OMB to ensure that agency proposed rules are “consistent with applicable law, the President’s priorities, and the principles set forth in  Executive order ,” and “that decisions made by one agency do not conflict with the policies or actions taken or planned by another agency.”
In a typical rulemaking, EPA would publish the proposed rule in the Federal Register after it passes OMB’s review (which typically takes two months).