You can do contracts, admin, scheduling, coding/billing / legal, HR, and admin your retirement accounts for 15% or less. Probably 12%.
If you employee the PAs, but also take the profit they make… its going to “cost” more (this can be 5-10% of revenue depending how many PAs you have) but of course unlike scheduling this cost feeds you $ right back. As such I like to separate it in my mind when I think about “overhead”.
As well, if your group is letting you throw money in a 403b and 457b, I don’t count this as “overhead” since it is going to you… it could be a significant % of your revenue.
The only one that messes up your math is malpractice. In certain parts of the country this can easily be 30k/yr per doc. Which could easily be 5% of the revenue. So YMMV, very dependent on location and nature of insurance.