Partnership/K-1 404 deduction limit

I know this has been discussed before, but looking for an answer  without having to read through a bunch of regulations, etc. etc.  Plan has 2 partners, no EEs.  They both get a K-1. Is the limit based on 25% of their combined net/earned income, or is the limit based on 25% of their individual net/earned income? 

Thanks -- 

Combined. You can use one partner's net earned income to substantiate a contribution for the other.

1 hour ago, C. B. Zeller said:

Combined. You can use one partner's net earned income to substantiate a contribution for the other.

Thank you! 

ratherbereading, we had a very long exchange of opinions on this two about years ago. An IRS Pub would seem to say individual, and you can get there under the statute and regs, although they are ambiguous. The majority of folks posting thought combined. I am surprised this has never been nailed down by IRS.

15 hours ago, Luke Bailey said:

I am surprised this has never been nailed down by IRS.

There are many, many things not nailed down by the IRS re: qualified plans.

52 minutes ago, BG5150 said:

There are many, many things not nailed down by the IRS re: qualified plans.

Agreed, but in this case you have a majority of practitioners going one way and an IRS pub going the other, year after year. And you have CPAs involved as well.