Is there a deadline for USCIS to decide on anasylum based I-485?

You can wait for the USCIS for years, even a decade in one example, as long as a client tolerates it. It can even claim that it already denied a case or that it closed the case because it is too many years since the interview. You have to keep filing inquiries and taking time off work. That is, unless you can get a Congressman to successfully intervene with an inquiry or hire an experienced immigration attorney to take the case to Federal Court.

The USCIS has an administrative duty to make a decision, but some are afraid to force the USCIS to make a decision. If you have a good case for adjustment, then an experienced attorney should discuss whether you can file what is called a writ of mandamus to order the USCIS to do its administrative duty based upon the Administrative Practices Act.

There is such a law that requires the USCIS NOT to be wilful and wanton or utterly reckless in making a decision. Unfortunately, many applicants are content waiting many months and even years, rather than paying an attorney to force a decision. Delaying is unwise, because facts can change and things can happen that can affect your rights.

This response is general information and does not create an attorney-client relationship.