California question

With California's Fair Housing issue on no discrimination for Marital Status, if two or more roommates applied would you combine their income and credit as you would a married couple, or if you ran them separately, requiring each one to qualify on their own, would that be a fair housing breach?

I would look at the credit individually. But as regards to income, I would look at the income combined and make sure the HOUSEHOLD income meets your requirements. In the event of roommates, I would make sure that they agree that if one of the roommates leaves, the remaining roommate must meet the income requirements on their own; either by increasing their income, or finding a new roommate that you can screen. Ideally, you will have roommates that will qualify on income individually anyway.

I might also consider accepting non-resident co-signers. In that case, make sure the co-signer makes at least 4 times the rent in income (because they have their own obligations to meet).