The service center that is responsible for reviewing the petition plays a critical role in the I-140 processing time. If the service center is experiencing a large caseload, it may take longer to process petitions. The service center that reviews your petition depends on the state and zip code from which the application is filed. The locator tool available on the United States Citizenship and Immigration Service’s website may be used to determine which service center will process the petition. It is possible to check the I-140 processing times for your specific green card using the USCIS Check Case Processing Time tool.