If the specimen is drawn or received by an independent laboratory approved under the Medicare program that performs a covered test, but the lab refers the specimen to another laboratory in a different carrier jurisdiction for additional tests, the carrier servicing the referring laboratory retains jurisdiction for services performed by the other laboratory.
Examples of Independent Laboratory Jurisdiction

EXAMPLE 1:  
An independent laboratory located in Oregon performs laboratory services for physicians whose offices are located in several neighboring States.  A physician from Nevada sends specimens to the Oregon laboratory.  If the laboratory sends the results to the physician and accepts assignment, the carrier in Oregon has jurisdiction.

EXAMPLE 2:  
American Laboratories, Inc., is an independent laboratory company with branch laboratories located in Philadelphia, Pennsylvania, and Wilmington, Delaware, as well as regional laboratories located in Millville, New Jersey, and Boston, Massachusetts.

The Philadelphia laboratory receives a blood sample from a patient whose physician ordered a complete blood count, an SMAC T-4, and a B12 and folate. The Philadelphia lab performs the complete blood count, but the SMAC T-4 is performed at the Millville lab, while the B12 and folate is performed at the Boston Lab. The Pennsylvania carrier retains jurisdiction for processing the claims if they have certification information and the appropriate fee schedule allowance in house. Otherwise, the local carrier servicing Boston and/or Millville has jurisdiction for processing their claims.
The Wilmington laboratory draws a blood specimen from a patient whose physician has ordered a blood culture. The Wilmington lab then sends the specimen to the Boston laboratory, which performs the required test. American Laboratories accepts an assignment for the service.

If the Delaware carrier has the capability of comparing the Wilmington lab’s charge for the blood culture against the appropriate reasonable charge screens for the Boston lab, the Delaware carrier will retain jurisdiction for processing the claim. If the Delaware carrier does not have this capability, the claim should be transferred to the Massachusetts carrier for processing.