The Project Management plan does indeed contain the Cost Baseline -- in fact, all of your baselines (scope, schedule, etc) are considered part of the PM plan.
However, that does not mean that the Cost Baseline is part of the Cost Management Plan. The Cost Management Plan is all about how you are going to plan, estimate, control, and report costs. So logically the Cost Management is an input for developing the Cost Baseline.
Moderators: Yolanda Mabutas, Ahmed Amin, Scott Gillard, Mary Kathrine Padua, ERIC BARTLETT, Gail Freedman, Kevin Nason, Steven Mudrinich, PMP, Mark Wuenscher, PMP, John Wolverton, Tracy Shagnea, PMP, Jada Garrett
This interview with Simona Fallavollita (LinkedIn Profile) was recorded at the magnificient Project Management Institute (PMI)® Global Conference 2017 in Chicago, Illinois. We discuss the how, what, why and when of the changes that are coming to the PMP exam.