Urgent care revenue is highly sensitive to Place of Service errors, especially POS 20 vs. POS 11 mismatches. A single incorrect code can trigger denials, underpayments, and patient copay disputes. Because payer contracts and credentialing rules vary, urgent care billing demands payer-specific oversight and routine audits. Practices that standardize POS workflows or use specialized billing support can protect reimbursement, reduce AR delays, and prevent systemic revenue leakage.