Does having a foreclosure and not paying your property taxes affect a US citizenship application?

If you are a lawful permanent resident who plans to file for citizenship, you would be well-advised to pay your property taxes and do whatever is in your power to avoid having a foreclosure on your credit record.  The Immigration and Naturalization Service (INS) does specifically ask questions about these matters.  Answering yes, alone, will not automatically cause your citizenship application to be denied, but you are going to have to provide detailed additional information to explain why these things happened.  Another important consideration is the fact that you have to prove that you are of good moral character and have been so for at least five years prior to applying for citizenship (although the INS can require you to prove good moral character for a longer period – five years is a minimum).  The taxes issue will affect this determination more strongly than simply having a foreclosure, and as a practical matter, if your property is mortgaged, the bank has probably kept the property taxes paid.