HL7 Integration Insights & Resources
Expert articles on HL7 v2, FHIR R4, EHR integration, HIPAA compliance, and healthcare interoperability — written by certified healthcare IT engineers.
What is HL7 Integration? A Complete Beginner's Guide
Discover the fundamentals of HL7 integration and its significance in healthcare and health tech — what HL7 is, why it exists, how the protocol works, and why it matters.
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Healthcare Software Product Development Company: Turning Innovative Ideas into Real-World Solutions
Taction Software is a top Healthcare Software Product Development Company building secure, scalable, HIPAA-compliant digital health solutions end to end.
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Elevate Your Data Security with Professional HIPAA-Compliance Consulting
Get expert HIPAA-Compliance Consulting across 50+ U.S. cities. Ensure data privacy, audit readiness, and full HIPAA compliance for healthcare & SaaS.
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HL7 ADT A01 Message: Complete Guide to Admit/Visit Notification
HL7 ADT A01 message structure, MSH, PID and PV1 segments, a full admission example, field mappings, Mirth Connect implementation, and troubleshooting.
Read More →HL7 ADT A02 Message: Patient Transfer Notification, Structure, Segments & Example
How HL7 ADT A02 transfer messages work — PV1-3 and PV1-6 locations, a sample message, Mirth Connect implementation, sequencing controls, and troubleshooting.
Read More →HL7 ADT A03 Message: Complete Guide to Discharge/End Visit Notification
HL7 ADT A03 discharge message structure, PV1-36 and PV1-45 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A05 Message: Pre-Admit a Patient, Structure, Segments & Examples
HL7 ADT A05 pre-admission message structure, PID, PV1 and PV2-8 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A07 Message: Change an Inpatient to an Outpatient
HL7 ADT A07 inpatient-to-outpatient change: ADT_A06 structure, PV1-2 patient class, key fields, a sample message, A07 vs A06 vs A03, and a Mirth Connect filter.
Read More →HL7 ADT A08 Message: Update Patient Information, Structure, Segments & Examples
HL7 ADT A08 patient update message structure, PID-3, PID-11 and PID-13 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A09 Message: Patient Departing, Message Structure, Segments & Examples
HL7 ADT A09 patient departing tracking structure, ADT_A09, PV1-3/6/11/42/43 location fields, A09/A10 correlation, A09 vs A02, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A10 Message: Patient Arriving, Message Structure, Segments & Examples
HL7 ADT A10 patient arriving tracking structure, ADT_A09, PV1-3 assigned vs PV1-11 temporary location, A09/A10 correlation, A10 vs A02, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A11 Message: Cancel Admit / Visit Notification, Structure, Segments & Examples
HL7 ADT A11 cancel admit/visit structure, ADT_A09, A01/A04 cancellation rules, PV1-19 encounter matching, A11 vs A03, A12, A13 and A38, examples, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A12 Message: Cancel Transfer, Structure, Segments & Examples
HL7 ADT A12 cancel transfer message structure, PV1-3 and PV1-6 location fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A13 Message: Cancel Discharge, Structure, Segments & Examples
HL7 ADT A13 cancel discharge message structure, PV1-19 and PV1-45 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A14 Message: Pending Admit, Structure, Segments & Examples
HL7 ADT A14 pending admission message structure, PV1-2, PV1-3 and PV1-19 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A15 Message: Pending Transfer, Structure, Segments & Examples
HL7 ADT A15 pending transfer message structure, PV1-3 and PV1-42 location fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A16 Message: Pending Discharge, Structure, Segments & Examples
HL7 ADT A16 pending discharge message structure, PV1-3, PV1-19 and PV1-45 fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A17 Message: Swap Patients, Structure, Segments & Examples
HL7 ADT A17 swap patients message structure, two PID/PV1 groups, PV1-3 and PV1-19 mapping, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A18 Message: Merge Patient Information, Structure, Segments & Examples
HL7 ADT A18 patient merge message structure, PID-3 surviving and MRG-1 prior identifiers, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A19 Message: Patient Query, Structure, Segments & Examples
HL7 A19 patient query workflows: QRY^A19 requests, ADR^A19 responses, QRD fields, full examples, Mirth Connect code, response correlation, and troubleshooting.
Read More →HL7 ADT A20 Message: Bed Status Update, Structure, Segments & Examples
HL7 ADT A20 bed status update structure, NPU-1 location and NPU-2 status fields, a full example, Mirth Connect code, ACK responses, and troubleshooting.
Read More →HL7 ADT A21 Message: Patient Goes on a Leave of Absence, Structure, Segments & Examples
HL7 ADT A21 leave of absence structure, ADT_A21, EVN-6 actual leave start, PV2-47 expected return, A21/A22 correlation, A21 vs A03, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A22 Message: Patient Returns From Leave of Absence, Structure, Segments & Examples
HL7 ADT A22 return-from-leave structure, the shared ADT_A21 message structure, PV1-19 encounter matching, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A23 Message: Delete a Patient Record, Structure, Segments & Examples
HL7 ADT A23 delete patient record structure, PID-3 identifier validation, a full example, safe Mirth Connect handling, ACK semantics, retention controls, and troubleshooting.
Read More →HL7 ADT A24 Message: Link Patient Information, Structure, Segments & Examples
HL7 ADT A24 patient linking structure, PID-3 and MRG-1 identifiers, link versus merge, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A25 Message: Cancel Pending Discharge, Structure, Segments & Examples
HL7 ADT A25 cancel pending discharge structure, ADT_A21, PID-3 and PV1-19 encounter matching, A25 vs A13, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A26 Message: Cancel Pending Transfer, Structure, Segments & Examples
HL7 ADT A26 cancel pending transfer structure, ADT_A21, PV1-3 current location and PV1-19 encounter matching, A26 vs A12, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A27 Message: Cancel Pending Admit, Structure, Segments & Examples
HL7 ADT A27 cancel pending admit structure, ADT_A21, A14/A27 correlation, PV1-19 pending encounter matching, A27 vs A11 and A38, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A28 Message: Add Person or Patient Information, Structure, Segments & Examples
HL7 ADT A28 add person information structure, ADT_A05, PID-3 identity and demographic mapping, duplicate prevention, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A29 Message: Delete Person Information, Structure, Segments & Examples
HL7 ADT A29 delete person information structure, ADT_A21, PID-3 identity validation, safe deletion and deactivation, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A30 Message: Merge Person Information, Structure, Segments & Examples
HL7 ADT A30 merge person information structure, ADT_A30, PID-3 surviving and MRG-1 prior identifiers, merge direction, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A31 Message: Update Person Information, Structure, Segments & Examples
HL7 ADT A31 update person information structure, ADT_A05, PID demographic mapping, field ownership and null handling, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A32 Message: Cancel Patient Arriving, Structure, Segments & Examples
HL7 ADT A32 cancel patient arriving structure, ADT_A21, PV1-19 encounter matching, A10/A32 tracking correlation, A32 vs A12, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A33 Message: Cancel Patient Departing, Structure, Segments & Examples
HL7 ADT A33 cancel patient departing structure, ADT_A21, PV1-19 encounter matching, A09/A33 tracking correlation, A33 vs A12, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A34 Message: Merge Patient Information, Patient ID Only, Structure, Segments & Examples
Legacy HL7 ADT A34 patient ID merge structure, PID-3 surviving and MRG-1 prior identifiers, merge direction, a v2.3 example, Mirth Connect code, ACKs, A40 migration, and troubleshooting.
Read More →HL7 ADT A35 Message: Merge Patient Information, Account Number Only, Structure, Segments & Examples
Legacy HL7 ADT A35 account number merge structure, PID-18 surviving and MRG-3 prior accounts, account vs visit numbers, a v2.3 example, Mirth Connect code, ACKs, A41 migration, and troubleshooting.
Read More →HL7 ADT A36 Message: Merge Patient ID and Account Number, Structure, Segments & Examples
Legacy HL7 ADT A36 patient ID and account merge structure, ADT_A30, PID-3/PID-18 surviving and MRG-1/MRG-3 prior identifiers, merge direction, Mirth Connect code, ACKs, A40/A41 migration, and troubleshooting.
Read More →HL7 ADT A37 Message: Unlink Patient Information, Structure, Segments & Examples
HL7 ADT A37 unlink patient information structure, ADT_A37 with two PID segments, A24 link vs A37 unlink, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A38 Message: Cancel Pre-Admit, Structure, Segments & Examples
HL7 ADT A38 cancel pre-admit structure, ADT_A38, PV1-2 preadmit class and PV1-19 visit matching, A05/A38 correlation, A38 vs A11, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A39 Message: Merge Person - Patient ID, Structure, Segments & Examples
Legacy HL7 ADT A39 patient ID merge structure, ADT_A39, PID-2 correct target and MRG-4 incorrect source, repeating patient groups, A39 vs A40, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A40 Message: Merge Patient Identifier List, Structure, Segments & Examples
HL7 ADT A40 patient merge structure, ADT_A39, PID-3 surviving and MRG-1 prior identifiers, merge direction, A40 vs A47, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A41 Message: Merge Account, Patient Account Number, Structure, Segments & Examples
HL7 ADT A41 account merge structure, ADT_A39, PID-18 surviving and MRG-3 prior accounts, merge direction, a full example, Mirth Connect code, ACKs, safe retries, and troubleshooting.
Read More →HL7 ADT A42 Message: Merge Visit - Visit Number, Structure, Segments & Examples
HL7 ADT A42 visit merge structure, ADT_A39, MRG-5 previous and PV1-19 surviving visit numbers, patient ownership checks, A42 vs A45 and A50, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A43 Message: Move Patient Information, Structure, Segments & Examples
HL7 ADT A43 move patient information structure, ADT_A43, the moved identifier in both PID-3 and MRG-1, source vs target identity, move vs merge, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A44 Message: Move Account Information, Patient Account Number, Structure, Segments & Examples
HL7 ADT A44 move account structure, ADT_A43, moving an account from source patient (MRG-1) to target patient (PID-3) with PID-18/MRG-3, move vs merge, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A45 Message: Move Visit Information - Visit Number, Structure, Segments & Examples
HL7 ADT A45 move visit structure, ADT_A45, moving a visit from source account (MRG-3) to target account (PID-18) with MRG-5/PV1-19, repeating MRG/PV1 groups, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A46 Message: Change Patient ID, Structure, Segments & Examples
Legacy HL7 ADT A46 change patient ID structure, ADT_A30, PID-2 new and MRG-4 previous patient IDs, change vs merge, collision checks, A46 vs A47, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A47 Message: Change Patient Identifier List, Structure, Segments & Examples
HL7 ADT A47 change patient identifier list structure, ADT_A30, PID-3 updated and MRG-1 previous identifiers, change vs merge, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A48 Message: Change Alternate Patient ID, Structure, Segments & Examples
Legacy HL7 ADT A48 change alternate patient ID structure, ADT_A30, PID-4 new and MRG-2 previous alternate IDs, change vs merge, collision checks, A48 vs A47, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A49 Message: Change Patient Account Number, Structure, Segments & Examples
HL7 ADT A49 change account number structure, ADT_A30, PID-18 replacement and MRG-3 previous accounts, change vs merge, billing reconciliation, A49 vs A41, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A50 Message: Change Visit Number, Structure, Segments & Examples
HL7 ADT A50 change visit number structure, ADT_A50, PV1-19 replacement and MRG-5 prior visit numbers, collision checks, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A51 Message: Change Alternate Visit ID, Structure, Segments & Examples
HL7 ADT A51 change alternate visit ID structure, ADT_A50, PV1-50 replacement and MRG-6 previous alternate visit IDs, PV1-19 context, A51 vs A50, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A52 Message: Cancel Leave of Absence for a Patient, Structure, Segments & Examples
HL7 ADT A52 cancel leave of absence structure, ADT_A52, EVN-2 vs EVN-6 timing, A21/A52 event matching, A52 vs A22 and A53, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A53 Message: Cancel Patient Return From Leave of Absence, Structure, Segments & Examples
HL7 ADT A53 cancel return from leave structure, ADT_A52, A22/A53 event matching, PV1-19 encounter identification, A53 vs A52, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A54 Message: Change Attending Doctor, Structure, Segments & Examples
HL7 ADT A54 change attending doctor structure, ADT_A54, PV1-7 XCN provider mapping, PV1-19 encounter matching, A54 vs A08 and A55, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A55 Message: Cancel Change Attending Doctor, Structure, Segments & Examples
HL7 ADT A55 cancel attending doctor change structure, ADT_A52, A54/A55 event matching, PV1-7 provider mapping, A55 vs A54, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A60 Message: Update Allergy Information, Structure, AL1 Segments & Examples
HL7 ADT A60 allergy update structure, AL1 and IAM segments, AL1-2 to AL1-6 mapping, allergy reconciliation rules, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A61 Message: Change Consulting Doctor, Structure, Segments & Examples
HL7 ADT A61 consulting doctor change structure, ADT_A61, PV1-9 provider mapping, multiple consultants and ROL dates, A61 vs A54, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →HL7 ADT A62 Message: Cancel Change Consulting Doctor, Structure, Segments & Examples
HL7 ADT A62 consulting doctor cancellation structure, ADT_A61, A61/A62 correlation, PV1-9 provider mapping, A62 vs A55, a full example, Mirth Connect code, ACKs, and troubleshooting.
Read More →What is HL7 Integration? A Complete Guide for Healthcare Organizations
A comprehensive introduction to HL7 messaging standards, interoperability concepts, message types, and why healthcare data exchange matters for modern clinical operations.
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HL7 v2 vs FHIR: Which Standard is Right for Your Integration Project?
Understand the key differences between HL7 v2 and FHIR R4, when to use each standard, and how to choose the right approach for your healthcare integration project.
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FHIR API Development Guide: Building Healthcare Interoperability in 2026
A practical guide to building FHIR R4 APIs — covering SMART on FHIR, resource types, authorization, and compliance with ONC and CMS interoperability rules.
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EHR Integration Best Practices: What Every Healthcare IT Team Should Know
Learn the proven strategies, architecture patterns, and common pitfalls to avoid when integrating with Epic, Cerner, Athenahealth, and other major EHR platforms.
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HIPAA-Compliant HL7 Integration: Security Requirements and Best Practices
Everything you need to know about building HIPAA-compliant HL7 integrations — encryption, audit logging, access controls, and meeting ONC security requirements.
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Healthcare Interoperability Benefits: The Business Case for HL7 Integration
Discover the clinical, operational, and financial benefits of achieving true healthcare interoperability through HL7 and FHIR integration — backed by real-world outcomes.
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HL7 Integration in US Healthcare: Meeting ONC and CMS Interoperability Requirements
A guide to navigating US healthcare interoperability mandates — the 21st Century Cures Act, ONC Final Rule, CMS Interoperability Rule, and what they mean for your HL7 strategy.
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Epic and Cerner Integration Guide: HL7 & FHIR Connectivity Explained
A deep dive into integrating with Epic and Cerner — comparing HL7 v2 interfaces, FHIR APIs, proprietary extensions, and practical tips from real-world integration projects.
Read More →HL7 ADT Messages Explained: A Complete Guide to Patient Event Notifications
A comprehensive look at HL7 ADT message types (A01–A60), key segments like PID, PV1, and EVN, and how to implement them with Mirth Connect in real healthcare systems.
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Healthcare Data Migration Strategies: Moving HL7 and FHIR Data Safely
How to plan and execute EHR-to-EHR data migrations — covering mapping strategies, validation, rollback planning, and HIPAA compliance during healthcare data migration.
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