Please use this secure portal to pay your bill for CareSpot, MedPost, or FastMed. CareSpot or MedPost billing questions? Call 866-765-2684, Monday - Friday, 9 AM - 7 PM ET. For FastMed - Texas billing questions, call 919-532-3700. Arizona patients only: For FastMed - Arizona billing questions, please call 480-545-1413 (Monday - Friday ....