or change of nonimmigrant status within the United States, the USCIS can issue its equivalent of Form I-94 as part of the I-797A approval notice. This applies to two main types of forms: Form I-129, Petition for a Nonimmigrant Worker, which can be used by a person already in the United States with authorization to change status to a temporary worker status. Note that Form I-129 can also be used by people currently outside the United States, but in that case, a Form I-797B approval notice is issued instead, and this does not include a Form I-94. Rather, in this case, the approval notice is used to obtain a temporary work visa, that the alien then uses to enter the United States and get a Form I-94 from CBP at the port of entry. Form I-539, Application to Extend/Change Nonimmigrant Status, which is used to change nonimmigrant status or extend one's stay on an existing status (beyond the expiration date of the Form I-94). An approval of Form I-539 is always accompanied by the USCIS issuing a new Form I-94. Note that for students on an F visa, the I-94's expiration date is listed as "D/S", for duration of status. Thus, stay is extended by having the student's SEVIS record updated and a new I-20 issued, without a new Form I-94 being issued. History Automation at sea and air ports in 2013 The switch away from paper Form I-94 to electronic Form I-94 was carried out in 2013. The change to I-94 definition to allow for the electronic format was recorded in the Federal Register on March 27, 2013. The rollout schedule was as follows: April 30: Chicago O'Hare, Charlotte Douglas, Orlando International, Las Vegas, Miami International, and Houston's Bush Intercontinental. May 7: Major air and sea ports corresponding to field offices in New York City, Boston, Buffalo, Baltimore, Detroit, Atlanta, Tampa, Puerto Rico, Miami, Chicago, New Orleans, and Houston. May 14: Major air and sea ports corresponding to field offices in San Francisco, Tucson, Arizona, El Paso, Texas, Seattle, Portland, Oregon (including Alaska), Los Angeles, San Diego, and Laredo, Texas. May 21: All remaining air and sea ports. Availability of online history On April 30, 2014, CBP announced a new retrieval tool that travelers could use to obtain their travel history and print their most recent Form I-94. Availability at land ports starting late 2016 In September 2016, CBP