Not if you're doing it for billing purposes, sure. But if your patient is a smoker and you're the only doctor he sees regularly (not an unusual situation), it's reasonable.
If you're doing it just for billing purposes, that's questionable. But if the billing is just there to provide some incentive for you to be thorough, that's different.
It's reasonable to hire a nurse to take vital signs, and you're already doing an MSE. Beyond that, it's probably good for your patient to just do some basic physical examination depending on the drug they're on - i.e. check for anticholinergic effects and/or serotonergic effects, get the nurse to do periodic ECGs on the patients that need them, get the nurse to draw blood for lithium levels or valproate levels, check for the classic side effects of the mood stabilizers, check for Parkinsonism in anybody on an antipsychotic, etc. And then throw in a thyroid exam, a neuro exam, etc. Only when there's an indication... not for every patient. But it'll mean that a lot of patients will get bumped up to that higher billing code (if they're not paying out-of-pocket), and you might actually pick up some things that you wouldn't have otherwise caught.
Plus, you don't even need the physical exam to bump up the billing code, as long as you have "moderate complexity decision making."