Lab Services Find the in-network status of laboratories throughout the United States. Please verify network status with the lab before you get care. Depending on where you get care, and whether you are enrolled in a plan that uses the Horizon PPO Network or the Horizon Managed Care Network, you may be able to use BioReference Laboratories, Laboratory Corporation of America Holdings, Inc. (LabCorp) and/or Quest Diagnostic (Quest) at the in-network level of benefits.