In USA If A Prctitioner Cause Cost More Than Allowed By Insurance Company For Example Orders Hospitilizing A Patient More Than Period Allowed By Insurance Who Have To Pay Extra Cost
A.patient
B.practitioner
C. Insurance Company But Their Would By Some Punishment For Practitioner

This appears to be a test,

But it is good to know, and I am shocked you don't know it.

The patient has to pay.
The insurance company only pays what it has to by policy
The doctor is due his pay.

Only exception is normally medicare, where the price is normally set by contract.

Thank.
The C. Option typo correction : " ... There would be some punishment for practitioner"
I don't live there but like to know your system.
So the doctor get paid. Does it means nothing will discourage unnecessary treatments unless the patient cannot afford it

Define unnecessary. You can report duplication of services, or request an EXPLANATION of any procedure they prescribe, including follow ups. Keep in mind all health insurance here is 80/20 at best, so expect those out of pocket expenses, unless you have SUPPLEMENTAL insurance. Most doctors I have dealt with are open to PAYMENT arrangements for those out of pocket expenses.

It comes down to being INFORMED about your policy, state law, and your doctor's network policy if they are part of one. Most Americans are covered under employer sponsored insurance, in which part of your premiums are paid by your job, the rest have no such discount thus higher premiums, co pays, and deductibles. Yes expensive.

Does it means nothing will discourage unnecessary treatments unless the patient cannot afford it
It is the patient's responsibility to not only question his practitioner as to proposed treatments and how they will affect the patient but also the patient needs to do his own research in reliable sources (medical journals, second and third opinions from other physicians, reliable medical websites) about his illness and possible treatments. In other words, a patient must be fully informed and be his own best advocate -- for his health's sake as well as for the sake of his finances.

The patient always has the right to refuse a treatment.

In general, payment of the balance is the patient's responsibility. However, if the care was rendered through a "managed care" arrangement (such as a health maintenance organization), state law may not permit "balance billing." The reason is that when the provider enrolled to be a provider to members of the HMO, he/she agreed to accept as full payment that which the managed care organization allowed.