In MS Planner, you can copy Tasks and Plans.

To copy a task:

  1. Hover mouse over the task.
  2. Click ··· opposite the task title, then select Copy task.

  1. Retain or change task title in the New task name field.
  2. Retain or change the major context by clicking Plan name field, then selecting the appropriate major context.
  3. Retain or move the task to a different column/bucket by clicking Bucket name field, then selecting the appropriate column/bucket.
  4. Click Copy.