Generally after 90 or 120 days,
depending upon their policy.
Why not call the Dr.
and set up a payment plan.
If you don`t want to ask them,
call an attorney or legal aid (free or reduced).
Usually they will answer such a simple question over the phone for free.
I am $30,000.00 in debt after 3 surgeries.
If you set up a plan - say $50.00 per mo and you make the payments on time and don`t miss a payment,
in most states,
they cannot put you in collection.
Most will want to work with you.
Thanks to our non-functioning economy,
MANY are in the same boat.
and work something out.
It is way better than ruining your credit score.