Does USCIS conduct a credit check if I want to sponsor my spouse for a green card?

I recently received the question at my Benicia office as to whether USCIS (United States Citizenship and Immigration Services) conducts a credit check of a sponsor when they petition for a spouse.  The answer is, “no,” they do not.  However, this does not let you off the hook financially.  A petitioner/sponsor sill must file an affidavit of support to show the government that the immigrating spouse will not become a public charge.  In other words, the sponsor will be promising the government that the immigrating spouse will not be applying for means-tested benefits (i.e, Food Stamps), because the sponsor has sufficient income.  This is not the same as a credit check but the sponsor will have to prove that he or she has income or assets over 125% of the Poverty Guidelines.  The sponsor will have to provide proof of income such as a copy of his or her federal income tax return from the past year.  Thus, while USCIS does not perform a credit check, your income is still checked.
if you are sponsoring your spouse, you will have to provide proof to USCIS  of your good faith marriage.  Such proof is typically documentation showing co-mingled financial assets.  If you do not provide proof of joint finances perhaps because you do not wish to comingle them or you do not want to affect your partner’s credit, you do not have to submit them, but then you should expect USCIS to question you as to why you are not submitting them.  You should plan on presenting more of other types of evidence so that USCIS understands you have a valid marriage.
Thus, while you do not have worry about your credit history when sponsoring your spouse, It is not a bad idea to make sure, to the extent that you are able, that your credit is okay.  You will need to provide proof to USCIS of joint cohabitation such as a lease agreement or utility bills.  Sometimes landlords and utility companies run credit checks.  So, while it is not USCIS that is running the credit check, another entity may be and you will need the documentation from that agency to prove your case.
There is another check that USCIS performs that does not relate to credit.  USCIS conducts a name/bio-data check of the Petitioner.  The purpose of this check is to make sure that the Petitioner does not have a conviction for one of the crimes under the Adam Walsh Act, ie., to make sure the Petitioner is not a registered sex offender.
Assuming you are not a sex offender, you should still be able to successfully petition for your spouse even if your credit is not the best.