It is incumbent on all nonimmigrants to “maintain continuously a lawful status.” There are negative consequences to failure to do so. Just for example, with rare exceptions (such as discretion for late filing due to circumstances beyond the person’s control and an otherwise squeaky-clean record), a person cannot change his or her nonimmigrant status to another type of status (for example, B-2 visitor to F-1 student), or extend his or her nonimmigrant status, unless already maintaining status.

Furthermore, with only a few limited exceptions (e.g., Immediate Relative spouse, parent or child of a U.S. Citizen; employment-based immigrant with less than 180 days of combined lack of status and unauthorized employment since last valid entry; lucky beneficiary of “grandfathering” under Section 245(i) of the Immigration and Nationality Act; etc.), a person who has been “out of status” for even a single day, at any time, cannot adjust status to Lawful Permanent Resident (“Green Card”).

Going out of status can also have negative consequences on visa renewals outside the U.S., since being out of status is a “violation” of a nonimmigrant entry.

The Illegal Immigration Reform and Immigrant Responsibility Act of 1996, commonly referred to as “IIRAIRA” or “IIRIRA,” added an unnecessary and, for many, disastrous wrinkle by introducing the concept of “Unlawful Presence” or “ULP.” Under INA section 212(a)(9)(B)(ii), a person is considered to be “unlawfully present” if he or she is in the U.S. “after the expiration of the period of stay authorized by the Attorney General,” or is in the U.S. “without being admitted or paroled.”

For people who entered the U.S. legally (“with inspection,” followed by “admission” or “parole”), ULP in general starts on the day the period of admission or parole expires. Some people are not admitted for a specific period. For example, F-1 Students, M-1 Vocational Students, and J-1 Exchange Visitors are admitted “D/S” (ironically standing for “Duration of Status”) rather than to a “date certain.” Canadians admitted as visitors are also considered admitted “D/S.”

For those admitted “D/S,” ULP starts, not when status expires, but only when the USCIS, or an Immigration Judge, determines that they are “unlawfully present.” Thus, for example, it is possible for a student whose student status has long ago expired, still not to be in a period of ULP. Similarly, a person in, say, H-1B status, who has been let go by his or her employer, is immediately “out of status,” since being employed by the sponsoring employer is a condition of maintaining status. He or she is not, however, “unlawfully present” until the earlier of the day after the full period of his or her H-1B admission expires, or the date USCIS or an Immigration Judge declares the person to be “unlawfully present.”

(Children by statute cannot accrue even a day of “unlawful presence” until their 18th birthday. Asylum applicants do not start accruing ULP while their applications are pending, unless during that time they have been employed “without authorization.” There are a few other exceptions. See INA section212(a)(9)(B)(iii).)

Why does it matter and who cares? It matters because many people, including alas many lawyers who should know better, incorrectly believe that NOT being “unlawfully present” is somehow legally the equivalent of being “in status.” Under this erroneous belief, they may try to change nonimmigrant status, or extend status, or adjust to LPR, despite being out of status, or, as attorneys, counsel their clients to do so, with potentially dire consequences. Ironically, one of those dire consequences is that they may wind up with enough ULP to cause real problems!

If there is one thing everybody needs to know and remember, it is that being “in status” is not legally the same as “not being unlawfully present,” and mere lack of “unlawful presence” is not the same as “maintaining lawful status.”

Here’s another thing everyone should remember: status is not extended by the timely filing of an application for change or extension of nonimmigrant status, or even by the timely filing of an application to adjust status to LPR. The only thing that extends status is a subsequent approval of such an application, in which case status is deemed to have been continuously in force retroactive to the date the status “expired.”

So, for example, if a person files while in status, but the status (last date on person’s I-94 admission record) expires while the case is being processed, the person is not “in status” after that date. The person generally does not accrue ULP during the processing, but may easily go out of status if processing extends past the end-date on the current I-94. If the application is subsequently approved, then no problem. If the application is denied, however, the person has been out of status since the previous I-94 expired, but only starts accruing ULP as of the date of the denial!

This is an important distinction, because there is nonetheless a benefit to “not being unlawfully present.” The same statute that defines ULP, prescribes that a person who has more than 180 days but less than 1 year of ULP, who departs from the U.S. and seeks to reenter, is subject to a “bar” of 3 years before he or she can reenter. A person with 1 year or more of ULP, is subject under the same circumstances to a 10-year bar.

Waivers of this bar are possible, but they generally require a “qualifying relative” (U.S. Citizen or LPR parent or spouse, not available for everybody) and a showing of “exceptional hardship” to that qualifying relative before the person may be allowed to reenter the U.S. At the same time, a person who has been out of status for years, but has managed not to accrue 180 days of ULP, in theory can, even if not eligible to change, extend or adjust status in the U.S., still process for a visa at a U.S. Consulate abroad. There are all sorts of ways a Consulate can still penalize an overstay with less than 180 days of ULP – Consular officers have a great deal of discretion – but the ULP bar is not one of them.

It is therefore crucial to monitor how many days of ULP a person accrues, even if not being ULP is not the same as being “in status.” In this regard, beware of another myth that is unfortunately all too prevalent even inside the Immigration lawyer community: that if an application is denied, and the person seeks an appeal or reconsideration of the denial, the accrual of ULP is “tolled” during the time the appeal or reconsideration is pending. Nothing could be further from the truth. An appeal or motion to reconsider or reopen a denial does not stop the ULP “clock” from running.

It is true that if the appeal or the motion is sustained, the person will retroactively be deemed not to have accrued ULP during that period. But if the appeal or motion is denied, and processing has taken more than 180 days, the person will have accrued more than 180 days of ULP, and perhaps fatally have limited his or her options going forward.

The "takeaway":  analyze "status" and "ULP" separately and do not confuse or conflate the two.  And monitor days of ULP fastidiously.