Fazlur Rahman
Enterprise cloud migration costs $500K-$5M+ depending on application count and complexity in 2026 (Source: AWS Migration Acceleration Program benchmarks, 2026). The 6 R's framework: Rehost, Replatform, Refactor, Repurchase, Retire, Retain. Rehost is cheapest ($1M-$2M for 100 servers); Refactor delivers best long-term TCO but takes longest. AWS MGN, Azure Migrate, GCP Migration Center provide the tooling. Timelines: 3-6 months (100 servers) to 18-36 months (1,000+ servers).
Last verified: Sep 14, 2026.
At a glance
- Cost: $500K-$5M+ for enterprise migration
- Rehost: fastest, cheapest; Refactor: most TCO benefit
- AWS MGN: $0 for 90 days, $0.042/hr/server thereafter
- Timeline: 3-6 months (100 servers) to 18-36 months (1,000+ servers)
- Mix of R strategies is typical
The 6 R's framework
AWS's 6 R's framework categorizes migration strategies by transformation depth. Most enterprises use a mix based on application priority, business value, and technical debt.
| Strategy | Description | Cost Impact | Time Impact | TCO Impact |
|---|---|---|---|---|
| Rehost | Lift-and-shift to cloud VMs | Lowest | Fastest | Modest (5-15%) |
| Replatform | Lift, make minor optimizations (e.g., managed databases) | Low-medium | Fast | Moderate (15-30%) |
| Refactor | Re-architect for cloud-native (microservices, serverless) | Highest | Slowest | Greatest (30-60%) |
| Repurchase | Move to SaaS (e.g., ServiceNow, Salesforce) | Medium (subscription) | Medium | Variable (SaaS TCO) |
| Retire | Decommission applications no longer needed | Cost savings | Fast | Direct savings |
| Retain | Keep on-premises for now (regulatory, technical reasons) | No change | None | None initially |
Source: AWS Migration Acceleration Program and AWS 6 R's framework, 2026.
Migration cost breakdown
Migration cost includes discovery, planning, tooling, professional services, and training. Most enterprises underestimate the change management and training portion.
| Cost Component | % of Total | Mid-Market ($1M-$3M) | Enterprise ($3M-$10M+) |
|---|---|---|---|
| Discovery & assessment | 10-15% | $150K-$450K | $450K-$1.5M |
| Migration tooling | 5-15% | $75K-$450K | $200K-$1.5M |
| Professional services | 30-40% | $300K-$1.2M | $900K-$4M |
| Re-architect (Refactor) | 15-25% | $150K-$750K | $450K-$2.5M |
| Testing & validation | 10-15% | $100K-$450K | $300K-$1.5M |
| Training & change management | 10-15% | $100K-$450K | $300K-$1.5M |
| Optimization post-migration | 5-10% | $50K-$300K | $150K-$1M |
Source: AWS Migration Acceleration Program benchmarks, 2026.
Migration tooling comparison
Each cloud has a primary migration platform plus third-party tools. AWS MGN, Azure Migrate, and GCP Migration Center provide unified discovery, assessment, and migration pathways.
| Cloud | Primary Tool | Database Tools | Cost |
|---|---|---|---|
| AWS | AWS Application Migration Service (MGN) | DMS, RDS, Aurora Babelfish | $0 first 90 days, $0.042/hr/server after |
| Azure | Azure Migrate | Azure Database Migration Service, Data Migration Assistant | Free tooling; pay for Azure services |
| GCP | Google Cloud Migration Center | Database Migration Service, BigQuery Data Transfer Service | Free tooling; pay for GCP services |
| Third-party | Carbonite Migrate, Zerto, Veeam, Movere | Various | License + service fees |
Source: AWS, Azure, GCP migration tooling documentation, 2026.
Migration phases
A typical enterprise cloud migration runs through 6 phases over 12 to 36 months. Skipping phases creates downstream rework.
| Phase | Duration | Activities |
|---|---|---|
| 1. Assessment | 4-8 weeks | Application portfolio inventory, dependency mapping, TCO analysis |
| 2. Planning | 4-8 weeks | Migration wave definition, landing zone, security, network design |
| 3. Pilot | 4-8 weeks | Migrate 5-10 application, validate tooling, refine runbooks |
| 4. Execution | 3-12 months | Migrate applications in waves, validate, decommission source |
| 5. Optimization | 3-6 months | Rightsizing, commitment purchases, FinOps implementation |
| 6. Operate | Ongoing | Run cloud operations, continuous optimization, governance |
Source: AWS Migration Acceleration Program and Microsoft Cloud Adoption Framework, 2026.
Internal links
See related cloud migration and cost guides: Multi-cloud cost management, AWS cost optimization, and Azure cost optimization.
FAQs
See FAQ section above for the 6 R's framework, migration cost ranges, AWS MGN / Azure Migrate / GCP Migration Center tooling, and Rehost vs Refactor guidance.
AWS Migration Acceleration Program benefits
AWS Migration Acceleration Program (MAP) provides funding and credits for qualifying migrations. MAP can offset 20-50 percent of migration costs through AWS credits and partner funding.
| MAP Tier | AWS Funding | Requirements |
|---|---|---|
| MAP Tier 1 (Assessment) | Up to $5,000 in AWS credits | Migration assessment with APN partner |
| MAP Tier 2 (Mobilization) | Up to $50,000 in AWS credits | Mobilization plan, business case, pilot migration |
| MAP Tier 3 (Migration) | Up to $250,000 in AWS credits | Full migration execution, 30%+ migrated within 12 months |
Source: AWS Migration Acceleration Program documentation, 2026.
FAQ expansion
Q: How long does a typical enterprise cloud migration take? Enterprise cloud migrations typically take 12-36 months depending on scope, application complexity, and chosen R strategy. Rehost migrations are fastest (6-12 months for 100 servers); Refactor migrations take longest (18-36+ months).
Q: What is the 6 R's of cloud migration? AWS's 6 R's framework: Rehost (lift-and-shift), Replatform (lift-tinker-shift), Refactor (re-architect for cloud-native), Repurchase (move to SaaS), Retire (decommission), Retain (keep on-premises). Most enterprises use a mix based on application priority and business value.
Q: Can I migrate to multiple clouds simultaneously? Yes, but most enterprises avoid it because of operational complexity. A primary cloud with selective workloads on second cloud (e.g., AWS for core, GCP for AI/ML) is more common than equal multi-cloud. Multi-cloud migration typically takes 24-48 months.
Cloud migration costs vary dramatically based on application complexity and chosen R strategy. A 100-server enterprise with mostly commodity applications can migrate for $500K-$1M. A 1,000+ server enterprise with complex custom applications requiring Refactor can spend $10M+.
Cloud Migration Acceleration Program (AWS MAP), Azure Migrate credits, and Google Cloud Migration Program provide funding and credits that can offset 20-50 percent of migration costs. Apply early to maximize benefit.
