Dependants hold L-2 status for the period granted to the principal, and it ends when the principal's does. A spouse in L-2 is employment-authorised incident to status, but that authorisation is tied to the status and does not survive it.
Short assignments need an exit plan too
A knowledge-transfer assignment framed as eighteen months creates a set of end dates that arrive quickly. School enrolment, a spouse's employment, a lease and a vehicle all get arranged around a period that is shorter than it feels at the start. Write down, at the beginning, what each family member's status permits and when it expires. If the spouse takes a job, that job ends with the status unless something else is filed in time, and employers do not always understand this. A child approaching twenty-one is the sharpest version of the same problem, because dependent status ends at that age regardless of the principal's remaining time. The five-year L-1B maximum also means that extensions are finite, so a family planning a longer stay should ask early what would follow.
Hypothetical example: A precision-optics technician will transfer for a system launch while a spouse plans to seek local employment and an eighteen-year-old expects to attend college. The first review should generate separate derivative files rather than assume the principal's technical record covers everyone. Passports and civil records establish the family connection; the principal's approved classification supports the derivative request. A spouse in valid L-2 classification may be employment-authorized incident to that status, subject to standard hiring evidence. A dependent child may study but does not receive work permission through L-2. Confirm admissions and expiry dates together, because family plans can outlast an initial project schedule.