[rayiner]

It depends on what kind of change in practice is at issue. Was it a practice that was dictated by rules? If so you need a new rule making. But I don’t believe that’s the case here. The memo here says that, to the extent decisions are within the discretion of immigration officers, remember that you don’t have to let anyone adjust their status.

You don’t need a rulemaking to release guidance on the exercise of discretion, even if that new guidance changes prior agency discretionary practice. Agencies do that all the time.