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Short answer: Epic Bridges and Epic Interconnect are the two foundational integration layers that connect an Epic electronic health record (EHR) environment to external clinical, laboratory, billing, and research systems. Epic Bridges is Epic’s built-in interface management toolkit for asynchronous, event-driven messaging—primarily pipe-delimited HL7 v2 and ANSI X12 transactions—handling message queuing, translation tables, and error recovery inside Epic Chronicles. Epic Interconnect is Epic’s external-facing web services gateway and middleware server that exposes synchronous HTTPS APIs, including Epic on FHIR (HL7 FHIR R4), proprietary RESTful endpoints, and SOAP/XML web services.
What is Epic Bridges and how does it manage HL7 v2 interfaces?
Epic Bridges is the application module and administrative framework inside Epic that configures, monitors, validates, and troubleshoots point-to-point clinical and operational interfaces. While hospitals frequently pair Epic Bridges with an external enterprise interface engine (such as Corepoint, Rhapsody, Mirth Connect / NextGen Connect, or Cloverleaf) to handle multi-system fan-out and network routing, Bridges governs how messages enter and leave the Epic Chronicles database.
Key technical responsibilities of Epic Bridges include:
- Event-Driven HL7 v2 Message Processing: When a clinician registers a patient, signs a laboratory order, or finalizes a radiology report in Epic, workflow triggers generate an outbound HL7 v2 message. Conversely, inbound interfaces parse incoming HL7 v2 segments (such as
MSH,PID,PV1,ORC,OBR, andOBX) and file discrete data into the patient chart. - Core Clinical and Financial Message Families:
- ADT (Admit, Discharge, Transfer): Real-time patient registration, census updates, bed movements, and medical record merges (e.g.,
ADT^A01,ADT^A04,ADT^A08,ADT^A40). - ORM and ORU (Order Entry and Unsolicited Observation Results): Laboratory, microbiology, pathology, and cardiology orders and structured result filing.
- SIU (Scheduling Information Unsolicited): Appointment bookings, cancellations, and reschedules across ambulatory and surgical systems.
- DFT and MDM (Detailed Financial Transactions and Medical Document Management): Charge capture feeds and transcribed clinical document headers.
- ADT (Admit, Discharge, Transfer): Real-time patient registration, census updates, bed movements, and medical record merges (e.g.,
- Translation Tables (AIF) and Interface Profiles (AIP): Because external laboratory information systems (LIS) or picture archiving and communication systems (PACS) often use local code sets, Epic Bridges maintains translation tables that map external codes to internal Epic Chronicles master file records (such as procedure codes, department IDs, or provider identifiers) before filing.
- Message Queues and Error Workqueues: Bridges tracks every inbound and outbound control ID, processes transport-level acknowledgments (
ACK/NAK) over TCP/IP Minimal Lower Layer Protocol (MLLP), and routes messages that fail validation (for example, an unmapped ordering provider or locked patient record) into structured Bridges error workqueues so interface analysts can resolve and reprocess them without losing clinical data.
What is Epic Interconnect and how does it expose web services?
Whereas Epic Bridges is designed for continuous, asynchronous message streams inside the hospital network, Epic Interconnect is Epic’s web services application server tier (deployed on Microsoft IIS / .NET infrastructure) that sits between external HTTP clients and the core Chronicles database.
Epic Interconnect handles synchronous, request-response communication patterns:
- HL7 FHIR APIs (DSTU2, STU3, and R4): All Epic on FHIR RESTful calls—whether launched by a clinician inside Hyperspace/Hyperdrive via SMART on FHIR, accessed by a patient through Epic MyChart, or queried by a backend service using OAuth 2.0 JWT bearer tokens—are served through Epic Interconnect.
- Epic-Specific REST and SOAP Web Services: For operational workflows not fully covered by standard HL7 FHIR resources (such as specialized appointment slot searches, real-time coverage verification, custom flowsheet filing, or legacy administrative integrations), Interconnect hosts Epic-authored REST/JSON and SOAP/XML web services cataloged in the Epic Showroom and Connection Hub.
- Security, Throttling, and Load Balancing: Interconnect terminates TLS connections, validates OAuth 2.0 tokens and client certificates, enforces client-specific API rate limits, and translates HTTP requests into internal Chronicles database calls without exposing the core database server directly to external networks.
Epic Bridges vs. Epic Interconnect: Architecture comparison
| Architectural Dimension | Epic Bridges | Epic Interconnect |
|---|---|---|
| Primary Standards | HL7 v2.x (pipe-delimited), ANSI X12 EDI, NCPDP | HL7 FHIR (R4/STU3/DSTU2), REST/JSON, SOAP/XML, IHE profiles |
| Communication Pattern | Asynchronous, event-driven push (trigger events and continuous queues) | Synchronous request-response pull/write (real-time API queries and posts) |
| Transport Protocol | TCP/IP with Minimal Lower Layer Protocol (MLLP) or batch SFTP | HTTPS (TLS 1.2+) with OAuth 2.0, OpenID Connect, or mutual TLS |
| Error Handling Model | HL7 ACK/NAK plus persistent Bridges error workqueues for manual/automated retry |
HTTP status codes (200, 400, 401, 422, 500) and FHIR OperationOutcome payloads |
| Typical Integration Targets | Reference labs, hospital LIS/RIS/PACS, state immunization registries, bed management | SMART on FHIR clinical apps, patient portals, mobile apps (Haiku/Canto), HIE document queries |
When does an Epic integration use Bridges versus Interconnect or FHIR APIs?
Health IT architects and clinical research informaticists select between Bridges and Interconnect—or combine both in a hybrid architecture—based on workflow trigger mechanics and data granularity:
- Use Epic Bridges when your system needs real-time event notifications: If a clinical trial matching engine, automated biobank specimen tracker, or ancillary imaging system must react immediately whenever any patient is admitted (`ADT^A01`) or a lab result is verified (`ORU^R01`), an event-driven HL7 v2 feed from Bridges avoids the overhead of continuously polling REST endpoints.
- Use Epic Interconnect (FHIR / REST) when an application needs on-demand chart context: When a clinician launches a decision-support tool or a clinical trial eSource platform pulls longitudinal medications, allergies, problems, and observations for a specific consented subject, synchronous FHIR R4 calls through Interconnect retrieve structured USCDI data on demand.
- Hybrid Bridges + Interconnect pattern: Many enterprise integrations use a lightweight HL7 v2 ADT or SIU message from Epic Bridges as the event trigger (notifying the external platform that a patient arrived for a clinic visit) and then immediately call Epic Interconnect FHIR R4 endpoints using the patient’s identifier to pull the full clinical context.
Frequently asked questions
What is Epic Bridges and how does it manage HL7 v2 interfaces?
Epic Bridges is Epic’s internal interface management module that sends, receives, translates, and monitors asynchronous HL7 v2 and X12 messages. It maps external code sets to Epic Chronicles master files using translation tables, tracks message delivery via TCP/IP MLLP acknowledgments, and captures failed messages in dedicated error workqueues so analysts can correct and refile them.
What is Epic Interconnect and how does it expose web services?
Epic Interconnect is Epic’s web services middleware server that exposes HTTPS endpoints outside the core Chronicles database. It handles authentication (such as OAuth 2.0 and SMART on FHIR), load balancing, and request routing for HL7 FHIR R4 APIs as well as Epic’s proprietary REST and SOAP web services.
When does an Epic integration use Bridges versus Interconnect or FHIR APIs?
Integrations use Epic Bridges for high-volume, event-driven broadcast streams—such as hospital-wide ADT census feeds, laboratory order/result (ORM/ORU) interfaces, and state public health reporting—and use Epic Interconnect (FHIR/REST) for interactive applications, patient-authorized data access, and on-demand queries for specific patient records.
