Physician groups bill separately from hospitals because the U.S. health system treats physician services and hospital facility services as distinct, billable items under different insurance rules. Many physician groups—especially emergency room physicians, anesthesiologists, and radiologists—operate as independent contractors rather than direct hospital employees, making them separate business entities.
This split billing structure applies across all insurance plans and is foundational to how U.S. healthcare pricing works. Understanding why it happens helps you anticipate multiple invoices and protect yourself from surprise bills.
Table of Contents
- The Medicare Structure Behind Separate Bills
- Independent Contractor Physician Groups
- In-Network Hospital Does Not Mean In-Network Doctor
- What the No Surprises Act Changed
- What You Can Do Before Treatment
- Frequently Asked Questions
The Medicare Structure Behind Separate Bills
The billing split reflects Medicare's payment system, which divides costs into two categories. According to The Hospitalist/MDedge article on physician payment systems, hospital facility services—the bed, nursing staff, equipment, and supplies—are billed under Medicare Part A, while physicians bill separately under Medicare Part B for their professional services: evaluation, diagnosis, treatment decisions, and interpretation of test results. For an emergency room visit, the hospital charges for the facility (space, monitoring equipment, nursing assessment), while the ER physician separately charges for their evaluation and medical decision-making.
These are genuinely different costs reflecting different work. That structure exists across all payers, not just Medicare.
Independent Contractor Physician Groups
Many physician groups, particularly in emergency medicine, anesthesia, and radiology, function as separate business entities. According to HCA Virginia's patient financial resources, emergency room physicians, anesthesiologists, and radiologists typically work as independent contractors who contract with hospitals to provide services but operate as separate entities, responsible for their own insurance negotiations and credentialing.
This arrangement exists partly because of economics. Emergency departments must see everyone regardless of ability or willingness to pay, and many patients pay nothing. That financial reality shapes how physician groups structure their independent billing relationship with hospitals, allowing them to manage their own revenue cycle and negotiate their own contracts.
In-Network Hospital Does Not Mean In-Network Doctor
one of the biggest surprises in hospital billing is that your insurance may cover the hospital but not the physicians treating you there. Even at a hospital your insurance considers in-network, the doctors, anesthesiologists, and radiologists may be out-of-network and outside your insurer's negotiated rates.
This happens because each physician must be individually credentialed and enrolled with every payer separately. You can receive multiple bills from providers you never chose and may not have known were out-of-network. A hospital's contract with your insurance covers facility charges, not the physician's professional fees, since the doctor is a separate business entity.
What the No Surprises Act Changed
The No Surprises Act, which took effect January 1, 2022, limits—but does not eliminate—separate billing. According to CNBC reporting, the law prohibits most surprise bills from emergency physicians, anesthesiologists, radiologists, and hospitalists treating patients at in-network hospitals without explicit patient consent. However, the law prevents out-of-network charges rather than separate billing itself.
Protected patients still receive multiple invoices from the hospital and from each physician group, but the physician's bill is capped at in-network rates. The billing split remains; the cost surprise is limited.
What You Can Do Before Treatment
You can reduce the risk of surprise bills by taking a few simple steps before a planned procedure or hospital visit. Contact your health plan to confirm whether each scheduled physician participates with your insurance. Call each physician group directly—the surgery center, anesthesiology group, or radiology group—and ask for a cost estimate and their billing practices.
According to TriStar Health's patient resources, patients should verify each physician's network status with their insurance before the procedure and ask in writing whether the group is in-network with your specific insurance plan. For emergency care, you have less time to prevent bills, but you can request itemized invoices immediately after treatment and verify charges against your in-network benefits.
Frequently Asked Questions
Why didn't the hospital negotiate my doctor's rates with my insurance?
Because your doctor may work as an independent contractor, not a hospital employee. Each physician must negotiate and credential separately with every insurance plan, even when working at an in-network hospital.
If I'm having surgery at an in-network hospital, are all my doctors guaranteed to be in-network?
No. The hospital's in-network status does not extend to physicians, anesthesiologists, or radiologists treating you there. Always verify each doctor's network status with your insurance before the procedure.
Does the No Surprises Act prevent all surprise medical bills?
The No Surprises Act prevents out-of-network charges for emergency physicians, anesthesiologists, radiologists, and hospitalists at in-network hospitals. However, you still receive separate bills—the law limits the charges, not the number of invoices.