I am about to close on a property this week and was informed by the title company that my marital status is listed as 'single' on all the bank documents but I am married. This apparently was a system glitch and we don't have time to change it now before closing. My question is: How can I change it to 'married' after I close on the property? Do I have to pay an attorney? I have no idea. Thanks

Your home is closing this week. It's not to late to change it!. Contact your Lender immediately so that documents can be redrawn.

As noted most likely you will have to move closing back, till you get new bank documents ( or the bank will have to make some real fast)
Things like this are not changed after closing.

Next don't you already have an attorney to review all of the closing material,