Call 212-562-5555 for during and after-hours clinical advice. Business Office/Billing: 212-562-6264. Patient Advocacy: 212-562-6071. Fax: 212-562-1597 or 212-562-1672. Specialty Clinics. The following specialty clinic services are available at NYC Health + Hospitals/Bellevue; a referral is required from your doctor: Allergy..