The global cloud-based EHR market is projected to reach $79 billion by 2027. Yet many healthcare organisations still operate legacy, on-premises Electronic Health Record systems built decades ago, which are expensive to maintain, difficult to scale, and incompatible with modern clinical workflows and emerging technologies like AI diagnostics and remote patient monitoring.Healthcare IT leaders face mounting pressure: ageing infrastructure demanding costly maintenance, clinicians frustrated by slow systems, compliance officers struggling with security complexity, and CFOs watching infrastructure costs climb. Meanwhile, competitive health systems have already moved to the cloud, offering faster systems and better operational visibility.This guide covers everything you need to know about migrating EHR/EMR workloads to the public cloud, from strategic planning and technical architecture to execution, compliance, and measuring ROI.Read: AI in Healthcare: How to Balance Personalization and Privacy

Understanding EHR Workloads

EMR (Electronic Medical Record) is patient medical history maintained by a single organization for internal use. EHR (Electronic Health Record) is designed for interoperability across multiple care settings, following patients across hospitals, specialists, and clinics.EHR systems are among the most demanding enterprise workloads. They require:

• Real-time access: Sub-second response times for instant patient information retrieval
• High concurrency: 5,000-10,000 simultaneous users performing transactions
• Massive data volumes: Terabytes of patient records, imaging, and clinical history
• Mission-critical uptime: 99.99%+ availability (roughly 50 minutes of downtime annually)
• Strict compliance: HIPAA, GDPR, and other healthcare regulations with encryption, audit logging, and access controls

Pre-Migration Assessment

Before migrating, conduct a comprehensive workload assessment (4-8 weeks):

Step 1: Inventory Everything

• All EHR modules, databases, and external integrations
• Dependencies and data relationships
• Custom code and technical debt
• Hardware and disaster recovery setup

Step 2: Choose Your Migration Strategy (The 6 R's)

StrategyBest ForProsConsRehost (Lift & Shift)Legacy systemsFast, low riskHigh ongoing costsRefactorDatabase tuningSome cloud benefitsLimited improvementRearchitectModernizationFull cloud benefitsLonger timelineRebuildCustom systemsFuture-proofHighest cost/riskReplaceSwitching vendorsMinimal IT overheadVendor lock-inRetireUnused systemsReduces complexityNone if unusedMost EHR migrations use a hybrid approach: Rehost the core EHR, Refactor supporting systems, and Rearchitect specific components for long-term value.

Step 3: Select Cloud Provider

FactorAWSAzureGoogle CloudHIPAA Compliance✓ BAA available✓ BAA availablePartialHealthcare ServicesAWS HealthLakeAzure Health Data ServicesGoogle Cloud Healthcare APIMarket ShareDominant in US healthcareStrong enterprise presenceGrowingCost ModelPay-per-use, competitiveReserved instances, hybrid benefitOften lowest storage costsRecommendation: AWS or Azure for most US healthcare organizations. AWS has more healthcare partners; Azure is stronger if you already use Microsoft infrastructure.

Cloud-Native Architecture

Modern EHR migration should move toward microservices architecture, not simply "lift-and-shift" the legacy monolith.

Industry Trends and Regulatory Outlook

Modern EHR migration should move toward microservices architecture, not simply "lift-and-shift" the legacy monolith.Key Components:

• Microservices: Independent clinical documentation, lab integration, pharmacy, imaging, and billing services—each scaled and deployed independently
• Data Architecture: Relational databases for structured data, object storage for images, event streams for real-time processing, data warehouses for analytics
• API-First Integration: RESTful APIs for internal communication, FHIR APIs for external interoperability
• Real-Time Processing: Event-driven architecture for clinical alerts and notifications
• Security Layer: Zero-trust architecture, encryption at rest and in transit, audit logging, and identity management

The "Strangler Fig" pattern enables phased migration: Keep the legacy system running while gradually replacing functionality with cloud-native microservices. This reduces risk and allows rollback.

Migration Execution

1. Phase 1 – Pilot (Weeks 1-12): Migrate non-critical workload (analytics, patient portal). Test cloud environment, validate performance and compliance.
2. Phase 2 – Wave 1 (Weeks 13-24): Migrate supporting systems (reporting, billing). Run parallel for 2-4 weeks, then cutover.
3. Phase 3 – Wave 2 (Weeks 25-48): Migrate core clinical systems using blue-green deployment or database replication for near-zero downtime (30 minutes to 2 hours vs. traditional 4-8 hour downtime).

Overcoming Common Challenges

1. Data Quality Issues: Pre-migrate data cleansing, validate completeness, establish reconciliation procedures.
2. Integration Complexity: Document all external integrations, standardize on FHIR APIs, use adapter layers for legacy systems.
3. Clinician Change Resistance: Minimize UI changes, involve clinicians early, provide comprehensive training, phase rollout by department.
4. Performance Issues: Database optimization, caching strategies, CDN for static content, load testing before cutover.
5. Runaway Cloud Costs: Implement cost governance, right-size instances, use reserved instances for steady-state workloads, adopt FinOps practices.

Financial Impact & ROI

CategoryOn-PremiseCloudSavingsHardware & Capex$2.5M$0$2.5MSoftware Licenses$2.4M$3.6M$(1.2M)Infrastructure$1.5M$2.8M$(1.3M)IT Staffing$3.6M$1.8M$1.8MMaintenance & Support$600K$200K$400KTotal 3-Year TCO$11.6M$9.8M$1.8M (15% savings)

3-Year Total Cost of Ownership: Break-even occurs by Month 18. Beyond cost savings, cloud enables clinical innovation, improves security, and enhances staff retention.

Compliance & Security

Cloud EHR systems must comply with HIPAA, GDPR, and other regulations. Key requirements:

• Business Associate Agreements with cloud providers
• Encryption: AES-256 at rest, TLS 1.3 in transit
• Access Controls: Multi-factor authentication, role-based access, audit logging
• Data Residency: US data in US regions, EU data in EU regions
• Incident Response: Documented breach notification procedures

Read: From Patient Records to Research Insights: The Impact of Data Quality in Healthcare

Conclusion

EHR cloud migration is a significant undertaking, but the payoff is substantial. Better clinical workflows, improved security, reduced costs, and agility to adopt emerging technologies.Next Steps: Conduct workload assessment, define migration strategy, select cloud provider, estimate costs, build business case, and secure executive approval. Start with a pilot, then execute phased migration using proven patterns like blue-green deployment. VE3 is a leading cloud solution provider having partnership with AWS, Google and Microsoft. Visit our cloud solution for healthcare. For more connect with us.