In 2008, Michael Chertoff, then Secretary of Department of Homeland Security during the Bush Administration, made the first use of parole-in-place for the spouse of a US Army soldier who was missing in action.  Department of Homeland Security then began granting parole-in-place to other military spouses on a case-by-case basis, but without any specific, announced policy.  On August 15, 2013, USCIS issued a policy memorandum setting out the requirements for parole-in-place for military spouses.

Parole-in-place may enable a foreign national who accured unlawful presence to adjust status to permanent resident while in the United States.  Usually when the spouse of a US citizen enters the United States illegally, that spouse may not adjust status (obtain permanent residence while inside of the United States and without having to leave). The unlawful presence bars at INA 212(a)(9) prohibit an alien who was inside of the United States illegally for a year or more and who departs from reentering the United States for 10 years. While there are waivers for the 10 year bar, they are difficult to get and carry a more expensive legal fee. Parole-in-place is available for the spouses of active duty US military service personnel, those honorably discharged from the United States military, and the US Ready Reserve if the reservist participated in at least forty-eight scheduled drills or training periods during each year of service and served on active duty for training at least fourteen days each year, or (2) participated in training at encampments, maneuvers, outdoor target practice, or other exercises at least fifteen days each year. But parole-in-place is also conceivably available to anyone the Secretary of Homeland Security chooses to give it to.

Parole-in-place is not humanitarian parole.  Humanitarian parole is an established benefit applied for using Form I-131 and I-134 used sparingly to bring someone who is otherwise inadmissibile into the United States temporarily due to a compelling emergency. It is not for obtaining parole while inside of the United States. Parole-in-place is an application for an alien who is already inside of the United States without lawful status to obtain permission to remain in the United States temporarily.  It is made on Form I-131 with a filing fee of $360 and filed with the USCIS District Office with jurisdiction over the applicant's place of residence.

The 1998 USCIS Memo by Paul Virtue HQCOU120/17-P issued August 21, 1998 provides that USCIS may in the exercise of discretion parole any applicant for admission including one who is already inside of the United States after entry without inspection if the USCIS finds that parole would serve urgent humanitarian reasons or yield a significant public benefit.  INA 212(d)(5)(A), 8 CFR 2.1.  Sean Olender recently obtained parole-in-place for a young child who entered the United States illegally with his mother and who was the beneficiary of a petition filed by his stepmother.  Because of child custdy disputes and other risks that could get out of hand if the child traveled home to consular process, USCIS granted the boy parole-in-place to avoid him having to return home to consular process.  Because he entered the United States illegally, he was not elgibile to adjust status to permanent resident while in the United States unless USCIS granted parole-in-place.