Mainframe Modernization Services
220 billion lines of COBOL code. 92% of developers retiring by 2030. Automated refactoring at $0.10/line changed the economics. Here's your escape plan before the 2027 talent cliff.
⚠️ The 2027 Talent Apocalypse
220,000 COBOL developers remaining (average age: 58.3). 92% retire by 2030. 47% of organizations can't fill COBOL roles today. Salaries rising 25%/year. You have 24 months to act before crisis pricing kicks in.
Top Mainframe Modernization Companies
| Company | Specialty | Cost | Our Rating ↓ | Case Studies |
|---|---|---|---|---|
| Astadia | IBM→Azure Migration | $$$ | ★4.5 | 14 |
| AWS Mainframe Modernization | Automated Refactoring (Blu Age) | $$$$ | ★4.4 | 18 |
| Modern Systems (Rocket) | Replatforming & Emulation | $$$ | ★4.3 | 16 |
| TCS | Assessment & Microservices | $$$ | ★4.1 | 22 |
| IBM Consulting | Hybrid Cloud Integration | $$$$ | ★4.0 | 28 |
| Deloitte | Strategic Innovation | $$$$ | ★4.0 | 15 |
| Accenture | Large-Scale Transformation | $$$$ | ★3.9 | 24 |
| Micro Focus (OpenText) | COBOL Emulation | $$ | ★3.9 | 12 |
| Kyndryl | Infrastructure Transformation | $$$$ | ★3.8 | 20 |
| DXC Technology | GenAI-Powered Services | $$$ | ★3.7 | 11 |
IBM→Azure Migration
Automated Refactoring (Blu Age)
Modern Systems (Rocket)
Replatforming & Emulation
TCS
Assessment & Microservices
IBM Consulting
Hybrid Cloud Integration
Deloitte
Strategic Innovation
Accenture
Large-Scale Transformation
Micro Focus (OpenText)
COBOL Emulation
Kyndryl
Infrastructure Transformation
DXC Technology
GenAI-Powered Services
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True Cost of Mainframe Migration Approaches
* Costs for 500K-1M LOC enterprise application. Excludes data migration and testing (add 30-40%).
Mainframe Modernization Market Share 2025
* Market share based on new modernization projects initiated in 2025.
Mainframe vs Cloud: The Real TCO
| COMPONENT | MAINFRAME (z/OS) | CLOUD (AWS) | SAVINGS |
|---|---|---|---|
| Compute (5,000 MIPS) | $4.2M/yr | $1.8M/yr | 57% |
| Licensing (z/OS, DB2, CICS) | $2.1M/yr | $0 | 100% |
| Storage (50TB) | $380K/yr | $120K/yr | 68% |
| Staffing (Ops + COBOL) | $1.2M/yr | $480K/yr | 60% |
| TOTAL (Annual) | $7.88M/yr | $2.40M/yr | 69.5% |
* Migration investment: $2.2M-$4M. Break-even: 12-24 months. Based on typical enterprise banking application.
Mainframe Modernization Strategy
Strategic guides on assessment, COBOL migration, and hybrid cloud.
Tactical Migration Guides
Technical patterns for specific mainframe migrations.
AS/400 (IBM i) to Cloud
→On AS400, the database and OS are one. RPG code relies on this tight integration (Single Level Store). Decoupling the logic from the database is the hardest technical hurdle.
COBOL to C# (.NET)
→COBOL's COMP-3 (packed decimal) has exact precision for financial calculations. C#'s decimal type is accurate but 10-20x slower than float. Vendors who use double/float will introduce rounding errors in currency calculations—a regulatory compliance disaster.
COBOL to Java
→COBOL uses fixed-point arithmetic (COMP-3). Java primitives (float/double) use floating point. Migrating financial logic blindly will result in rounding errors. Ensure vendor uses BigDecimal or a dedicated money library.
Mainframe to AWS
→Moving data out of AWS back to on-premise systems (for hybrid scenarios) can be incredibly expensive. Architect your VPC endpoints and Direct Connect links carefully to minimize traversal costs.
Mainframe (z/OS) to Azure
→Mainframe security (RACF/TopSecret) is granular and dataset-based. Azure Entra ID (Active Directory) is role-based. Mapping these permissions without opening security holes is a major audit risk.
Mainframe Modernization FAQ
Q1 What happens when our last COBOL developer retires?
47% of organizations can't fill COBOL roles today. Salaries are rising 25%/year. By 2027, 92% of remaining COBOL developers will have retired. Your options: automated refactoring ($0.10-$0.30/line), offshore contractors ($180-$250/hour), or emergency rewrite at 3x cost. Start now or pay the crisis premium.
Q2 How much does mainframe modernization really cost in 2025?
$400K-$5.2M depending on approach. Rehosting (emulator) costs $600K, 6-12 months. Automated refactoring costs $2.2M, 12-24 months. Full rearchitecting costs $4M, 24-48 months. Average dropped from $9.1M in 2024 to $7.2M in 2025 due to AI-powered automation. Break-even: 18-36 months.
Q3 Is automated COBOL-to-Java conversion actually reliable?
70-85% automation rate in 2025 (was 40% in 2020). AWS Blu Age charges $0.10/line after 120K free tier. Remaining 15-30% requires manual cleanup. Success factors: well-structured COBOL (not spaghetti code), comprehensive test suite, and 40% of budget for UAT. Failure risk if you skip data migration planning (VSAM→Postgres is the hard part).
Q4 Should we rehost, refactor, or rearchitect our mainframe?
Rehost if timeline <18 months or just need MIPS cost reduction (40-60% savings). Refactor if talent crisis is primary driver and codebase is 500K-2M lines. Rearchitect if strategic transformation and you have 24-48 months. Hybrid (78% of companies) if you need both: mainframe as system of record, cloud for new apps. Never do big-bang cutover.
Q5 What's the real cost per MIPS in 2025?
$840-$1,200/MIPS/year on IBM z/OS vs $340/vCPU-equivalent/year on AWS (60-75% savings). Hidden costs: MIPS licensing is capacity-based (you pay even if idle), $0.03-$0.12 per API call, data transfer fees. Example: 5,000 MIPS workload = $7.88M/year mainframe vs $2.40M/year cloud. But migration costs $2.2M-$4M upfront.
Q6 Can we keep our mainframe and modernize?
Yes. 78% use hybrid model: mainframe as system of record, cloud for new customer-facing apps. Strangler fig pattern: incrementally move business logic to microservices, leave data on mainframe. Benefits: risk spread over time, ROI from day one. Downside: dual-stack operational complexity, still dependent on COBOL talent for core system.
Q7 What's the biggest risk in mainframe modernization?
Underestimating testing (allocate 40% of budget for UAT, not 20%). Ignoring data migration complexity (VSAM→Postgres requires domain experts, not just DBAs). No rollback plan (you need 6+ months parallel run). Vendor lock-in to emulator or refactoring tool. And the #1 killer: stakeholder assumption that 'COBOL in Java' is cloud-native. It's not.
Q8 How long until we HAVE to migrate off mainframe?
2027 is the cliff. 92% of COBOL developers retire by 2030. Average age today: 58.3 years. Universities stopped teaching COBOL 20+ years ago. By 2026, you'll pay 3x for contractors. By 2028, your system becomes unmaintainable. Start assessment in 2025, begin migration in 2026, complete by 2028. You have 24 months to act before the rush.