Federal law allows a youth minimum wage of $4.25 an hour for employees under 20, but only for the first 90 consecutive calendar days of employment with that employer. Calendar days, not working days — so it expires roughly three months after the start date whether you worked one shift a week or five. Employers may not displace other workers to use it, and many states do not allow it at all.
The 90-day rule is the whole thing
Ninety consecutive calendar days from the first day of employment. The clock runs whether or not you work, so a part-time job that ran two shifts a week is on the full rate after the same three months as a full-time one.
It also attaches to the employer, not to you. Ninety days at one employer does not use it up at the next, and turning 20 ends it immediately whatever the calendar says.
What it does not allow
Displacing existing employees to take advantage of it, including by cutting hours. That is prohibited outright, and it is the condition most likely to be breached in practice.
Student learners and full-time students
Separate certificate programs allow reduced rates for some student learners in vocational training and for full-time students in retail, agriculture and at their own institutions. Each requires an actual certificate from the Department of Labor and each carries limits on hours and on the proportion of a workforce.
An employer paying a reduced student rate without holding the certificate simply owes the full minimum.
State law frequently overrides it
Many states do not permit a youth subminimum at all, or set one much closer to the full rate. Where the state rule is more protective it governs, which means the federal $4.25 is unavailable across a large part of the country.
The two questions worth asking
When did my 90 days start, and does my state allow this at all. Both have documentary answers, and a rate that continues past day 90 is a straightforward wage claim.
Common questions
What is the youth minimum wage?
$4.25 an hour under federal law for employees under 20, limited to the first 90 consecutive calendar days with that employer.
Is that 90 working days?
No, 90 consecutive calendar days. The clock runs whether or not you work, so part-time and full-time reach the full rate at the same point.
Does it reset at a new employer?
Yes. It attaches to the employer rather than the worker, and turning 20 ends it immediately.
Can an employer cut someone's hours to hire at the youth rate?
No. Displacing existing employees to use it, including by reducing their hours, is prohibited.
Do all states allow it?
No. Many do not permit a youth subminimum or set one closer to the full rate, and the more protective rule governs.