On May 10, 2018, USCIS posted a policy memorandum changing the way the agency calculates unlawful presence for those who were in student (F nonimmigrant), exchange visitor (J nonimmigrant), or vocational student (M nonimmigrant) status.
The revised final memorandum published on August 9, 2018 supersedes May 10th memorandum and describes the rules for counting unlawful presence for F and M nonimmigrants with timely-filed or approved reinstatement applications, as well as for J nonimmigrants who were reinstated by the Department of State.
For purposes of counting unlawful presence, a timely reinstatement application for F or M status is one where the student has not been out of status for more than five months at the time of filing. Under the revised final policy memorandum, the accrual of unlawful presence is suspended when the F or M nonimmigrant files a reinstatement application within the five month window and while the application is pending with USCIS.
If the reinstatement application is denied, the accrual of unlawful presence resumes on the day after the denial.
Accrual of unlawful presence could result in later inadmissibility under section INA 212(a)(9).
Whether or not the application for reinstatement is timely-filed, an F, J, or M nonimmigrant whose application for reinstatement is ultimately approved will generally not accrue unlawful presence while out of status.
The Department of State administers the J-1 exchange visitor program, to include reinstatement requests. If the Department of State approves the reinstatement application of a J nonimmigrant, the individual will generally not accrue unlawful presence from the time the J nonimmigrant fell out of status from the time he or she was reinstated.
Memorandum is here.