When you charge for phlebotomy you have the option to be more specific about where the draw takes place, and the prices you charge in each scenario.
By setting a global action from your Account > Settings page, you can specify prices for specimen drawn outside your clinic, or specimen drawn inside your clinic. The options are labeled as such:
External Phlebotomy Charge
This charge will be added when the patient has specimen drawn at an external labs facility.
Internal Phlebotomy Charge
This charge will be added when the patient has specimen drawn at your clinic.
The prices you set at your account level will be reflected as you order labs through your usual process.