Automatically passing the value of a field to a field in a different content type

I have a content type A with a personID field (unique number). After I choose a particular node from a view (a list of people), I need to "save" the value of the personID field for that node and then automatically enter that value into the ID field of a different content type B when I go to create a new node of content type B. Can I simply set the default value somehow? Should I write a custom module with php code to set the value of the ID field? Thanks!