Filing for bankruptcy while you are married, will likely affect your spouse's credit no matter what. The questions are how will it specifically affect debt and your property if you are married and choose to file as an individual. When dealing with debt and property, it first depends what state you live in, either community property state or equitable division (or common law). This specific laws are important because they have to do with what your specific rights are in your property in the marriage, and whether your debts are shared with one another and how.
When looking at common law property states (the majority of the states in the country), there is a very clear distinction between property: marital and separate. Anything that was acquired during the time of you and your spouse's marriage, is considered to be marital property; however if you came into the marriage with a home, inheritance, etc. then these would remain separate property. For example, if you and your spouse to where get a divorce, the separate property could not be taken over by your ex in the split if you do not wish it so. Under this category when dealing with bankruptcy, anything that you own separately as well as your portion of the property you share with your spouse can be gone after by creditors or affected by your dealing with debt or filing for bankruptcy.
Essentially, if you are struggling with debt and decide to file as an individual, anything that your spouse is attached to that is yours may be affected. However, in most cases, choosing to file for bankruptcy and address the debt situation is a far better deal than risking the potential a creditor is going to come after you. Certain debts are considered to be discharged if you file for this individual bankruptcy and if this is the case then if your spouse has any debt, they are still responsible to pay that back while you are covered by bankruptcy.
If you and your spouse live in a community property state (California, Arizona, Idaho, Nevada, Louisiana, New Mexico, Washington, Texas, or Wisconsin) then filing for bankruptcy as an individual will be very different than in a common law state. The main reason is that a community property state generally means that together you basically own everything together, whereas in the other classification it is much easier to distinguish between what is his and hers. Under this category, all of your community property is subject to the bankruptcy filing even if you filed alone. It is important to realize that if you live in one of these states, your community property will actually be at greater risk if you file apart from your spouse. Because of this, you will want to make sure that your property is exempt and therefore protected in the bankruptcy filing.
However, anything that is considered to be separate property is kept as separate from the bankruptcy filing as well and is therefore unexpected by your filing if it is your spouse's only. When dealing with bankruptcy as a married couple though only one of you files, it is important to realize that in both property states; only your debt will be dealt with. If your spouse has any sort of debt, even though you file for bankruptcy, they are still entirely responsible for paying that off.
Filing for bankruptcy can be a complicating process, and for that reason before you make any decisions on whether to file alone or as a couple, contact a bankruptcy attorney in your area for the legal expertise you want on your side.