Question about cumulative sum

[LengYi]

Hi everyone,

I have some issues to ask about how to coding in SAS.

Well I have data looks like:

I want to do a cumulative sum column "Paid" but only after default month will be used to sum. (in the yellow and blue cell)

And I want to a cumulative sum separated by ID.

Any segesstion?

Thank you

[PeterClemmensen]

Please do not double post 🙂