This article explains how to copy a PowerPoint design template to another presentation. Instructions apply to PowerPoint 2019, PowerPoint 2016, PowerPoint 2013, and PowerPoint for Microsoft 365.
How to Copy Slides to Another Presentation – Best Method
It's often faster to copy a design template from a presentation than to search for it in the list of PowerPoint templates.
In the presentation containing the design template you want to copy, go to View and select Slide Master.
Right-click the slide master in the slide pane on the left side of the screen and select Copy.