They’re capped at 80 hours per week, more or less. Most residents go over, regularly. But a single report of a work hours violations is a pretty serious deal for a residency program, so that alone means things are better than they used to be. On the other hand, programs tend to use everything from coercion to collective punishment to prevent these reports from being filed. In practice, this seems to work out as residents tolerating a certain amount of extra hours, as a matter of culture (this varies by institution and by specialty), but it doesn’t seem to be as bad as the old days. Just my limited perspective as a partner to a surgical resident.