use regular expression to find data and so it can be marked for redaction

Data to be found and marked for redaction looks like this:

I50name initial. name, 0000

or
I50mr. name name, jr., 1111

data to be marked should be the last 4 digits

every line will end with 4 digits

i am having trouble trying to account for data that may or may not be in all lines that i am trying to find that start with I50 and end with 4 digits