Top Companies for Mainframe Modernization in 2026

You might have heard that businesses are migrating their mainframe systems to the cloud for better scalability, security, and cost-effectiveness. In fact, the top mainframe modernization companies are the pillar keeping core business logic intact while driving transformation.

We used to think the same until we came across an IBM report stating that mainframe technology is still used by 45 of the top 50 banks and 67 of the Fortune 100 companies. Surprising, isn’t it?

Mainframe solutions carry a huge responsibility, and yet no one knows when they might fail. These outdated systems leave businesses vulnerable to unexpected outages, security gaps, and the risk of losing market share.

Roughly 90% of decision-makers believe that legacy systems are holding their business back in terms of growth and efficiency.

In 2026, legacy mainframe solutions will become an even greater liability. They are costly to maintain, hard to scale, and extremely unreliable. And the lack of mainframe modernization experts is just making it worse.

On the flip side, the enterprises that have taken the step to modernize their mainframe systems are already seeing substantial benefits.

For example, in the insurance sector, companies that modernized their systems saw claim cycle times reduced from 7 days to under 48 hours. Similarly, in the financial sector, organizations achieved sub-10 ms trade execution latency through legacy application modernization.

These success stories demonstrate how vital mainframe modernization services will be in the year 2026.

It will not be fair to link mainframe modernization to a single sector. Various business domains rely on mainframes and are prioritizing modernization by partnering with the top companies for mainframe modernization.

Some of the top sectors are:

• Banking and Financial Services

BFSI dominated the mainframe modernization market with 32% market share in 2024. Banks rely on mainframes for core banking, transaction processing, and regulatory compliance. Mainframe modernization services enable real-time payments, mobile banking innovations, and integration with fintech platforms.

• Healthcare

Healthcare is one of the fastest-growing segments for legacy modernization initiatives on mainframes. Providers are modernizing their legacy systems to enhance patient data management, enable telemedicine platforms, and integrate with digital health applications.

The shift to value-based care requires data analytics capabilities that legacy systems can’t support.

• Insurance

Insurance companies process millions of policy transactions daily on mainframes. Mainframe modernization enables them to launch digital-first products, provide instant quotes, and integrate with insurance marketplaces.

• Government

Government agencies manage vast amounts of citizen data on mainframes, from social security to unemployment systems. The top mainframe vendors help organizations modernize their systems to improve citizen services, enable digital portals, and reduce the risk of system failures that can affect millions of people.

• Retail and E-Commerce

Large retailers use mainframes for inventory management, supply chain optimization, and transaction processing. App modernization services help retailers connect these systems to e-commerce platforms, enabling omnichannel experiences and real-time inventory visibility across physical and digital channels.

We did the heavy lifting for you. We evaluated and compiled a list of the top mainframe modernization companies. To get there, we scrutinized each firm against key factors. Experience, expertise, past projects, client feedback, and, of course, affordability, along with a few other factors, were considered.

• Deep Technical Expertise

We prioritized companies with proven experience in mainframe application modernization across multiple legacy platforms, including COBOL, PL/I, Assembler, and proprietary languages. The best firms don’t just migrate code; they understand business logic embedded in decades-old systems and preserve it during modernization.

• Comprehensive Service Offerings

Top mainframe modernization companies offer end-to-end services: assessment and planning, automated code analysis and refactoring, cloud migration and replatforming, hybrid modernization strategies, DevOps integration, and post-modernization support. One-trick ponies didn’t make our list.

• Proven Automation and Innovation

Manual code conversion is too slow, too expensive, and too error-prone. We looked for vendors that leverage AI-powered code analysis, automated testing frameworks, intelligent refactoring tools, and accelerators to reduce timelines and risks.

• Verified Client Success

We examined case studies, client testimonials, and independent reviews from platforms like Clutch and Gartner. Companies needed documented evidence of successful modernization projects, not just marketing claims.

• Scalability and Flexibility

Large-scale mainframe transformation requires companies that can scale teams, adapt to different methodologies, and provide flexible engagement options. These can range from full outsourcing to offering dedicated development teams and consulting and advisory services.

Additionally, mainframe vendors that support agile software delivery (or other approaches as needed) made our list of top companies for mainframe modernization.

• Industry Recognition and Partnerships

We considered certifications like AWS Partner status, ISO compliance, and recognition in industry analyst reports. Strategic partnerships with cloud providers and technology vendors demonstrate a commitment to staying current with modernization best practices.

Code District earns the number one spot on our list of the top mainframe modernization companies. The company helps organizations understand the true value of their mainframe solutions through modernization.

The team at Code District understands business needs, selects the right mainframe modernization approaches, and executes them to perfection. Code District helps enterprises reduce technical debt and long-term maintenance costs.

Code District specializes in integrating mainframe systems with cloud services using APIs. The company is also proficient in adding AI capabilities to your systems.

Code District has a solid track record of modernizing applications for large enterprises. And the best part? Their clients are clearly happy, which you can see from the feedback on platforms like Clutch.

Regarding certifications and accolades, Code District earned a spot on the 2025 Inc. 5000 list of Fastest-Growing Companies, reflecting its proven track record of helping enterprises transform legacy systems.

They’re ISO 9001 and ISO 27001 certified, an AWS Partner, and a member of the Forbes Business Council.

Key Services

• End-to-end mainframe modernization solutions
• COBOL, PL/I, and legacy application re-architecture
• Cloud-ready solutions for hybrid cloud environments
• Custom-tailored mainframe modernization strategies
• Automated code refactoring and testing
• Post-modernization support and optimization

Company Overview

• Min Project Size: $10,000+
• Hourly Rate: $25-$49/hour
• Team Size: 250-999 employees
• Founded: 2017

Astadia specializes in rapid mainframe-to-cloud migration, helping large enterprises move mission-critical applications quickly and reliably. The company helps businesses choose the best mainframe modernization strategy for their needs.

Astadia has completed hundreds of modernization projects for Fortune 500 companies across financial services, insurance, and government sectors. Their Fast Track methodology accelerates timelines while reducing risks associated with big-bang migrations.

Key Services

• Mainframe-to-cloud migration
• End-to-end modernization 
• Expertise in application replatforming
• Fast, reliable cloud migration 

Company Overview

• Min Project Size: $100,000+
• Hourly Rate: $50 – $99/hr
• Employees: 1,000+
• Founded: 2000

Swimm offers an Application Understanding Platform designed to tackle one of the biggest challenges in mainframe modernization: understanding and documenting complex legacy code. This tool uses deterministic static analysis combined with generative AI to automatically reverse-engineer legacy systems, helping modernization teams gain clarity into architecture, business logic, and code dependencies.

Swimm is particularly powerful at extracting business rules, mapping program structures, and turning cryptic legacy code into human-readable insights. Its platform supports languages and frameworks common in mainframes, such as COBOL, CICS, and PL/I.

Key Services

• Automated legacy code discovery and documentation
• Business rule and logic extraction
• Architectural overviews and dependency mapping
• Enhanced code comprehension with natural-language explanations
• Support for secure enterprise deployments

Company Overview

• Min Project Size: Typically enterprise customization (varies)
• Hourly Rate: Custom/enterprise pricing
• Employees: 11-50
• Founded: 2019

Micro Focus provides comprehensive COBOL refactoring and rehosting tools that enable organizations to modernize without complete rewrites.

Their Enterprise Suite allows businesses to migrate mainframe workloads to cloud platforms while preserving existing code, dramatically reducing migration risks and timelines.

Key Services

• COBOL refactoring and cloud migration
• Automated testing and validation to reduce risks
• Micro Focus Enterprise Suite for mainframe modernization
• Strong focus on security and compliance for regulated industries

Company Overview

• Min Project Size: $50,000+
• Hourly Rate: $50 – $99/hr
• Employees: 12,000+
• Founded: 1976

Accenture ranks among the top companies for mainframe modernization brings massive scale, industry expertise, and advanced modernization frameworks to enterprise-level transformations.

Using mainframe modernization tools like myNav for assessment and planning, Accenture delivers a comprehensive digital transformation that extends beyond mainframe modernization to include business process reengineering and organizational change management.

Key Services

• Enterprise-level mainframe replatforming
• Integration of AI, automation, and cloud technologies
• Advanced modernization frameworks for comprehensive digital transformation
• Proven track record in banking, insurance, and government

Company Overview

• Min Project Size: $250,000+
• Hourly Rate: $100 – $149/hr
• Employees: 500,000+
• Founded: 1989

TSRI provides an automated COBOL-to-Java transformation that preserves business logic while modernizing codebases.

Their automated translation platform accelerates modernization timelines significantly compared to manual rewriting, reducing both cost and risk.

Key Services

• Automated code translation from COBOL to modern languages
• API generation for easier integration with modern systems
• Cloud migration support for hybrid environments
• Code analysis and refactoring to improve maintainability

Company Overview

• Min Project Size: $100,000+
• Hourly Rate: $50 – $99/hr
• Employees: 500 – 999
• Founded: 1997

Heirloom focuses exclusively on cloud-native COBOL transformation, enabling seamless migration to modern Java architectures.

Their platform facilitates DevOps integration from day one, enabling modern applications to leverage CI/CD pipelines, containerization, and other development practices immediately.

Key Services

• COBOL to Java conversion for cloud-native deployments
• DevOps-ready platforms for continuous integration
• Cloud-native modernization to leverage scalability and performance
• Seamless transition from mainframe to cloud infrastructure

Company Overview

• Min Project Size: $200,000+
• Hourly Rate: $100 – $149/hr
• Employees: 100 – 250
• Founded: 2000

Raincode specializes in COBOL compilation to .NET and JVM platforms, enabling gradual modernization strategies.

Their compiler technology allows organizations to modernize incrementally, reducing the “big bang” risks associated with complete system replacements.

Key Services

• COBOL to .NET/JVM compilation
• Refactoring and modernization for legacy systems
• Cloud migration support for hybrid environments
• Integration with modern DevOps workflows

Company Overview

• Min Project Size: $25,000+
• Hourly Rate: $50 – $99/hr
• Employees: 50 – 249
• Founded: 2008

CloudFrame offers automated mainframe-to-microservices transformation, breaking monolithic applications into modern, scalable architectures.

Their platform integrates directly with DevOps pipelines, enabling continuous modernization rather than one-time transformations.

Key Services

• Microservices transformation from legacy systems
• Cloud-native deployment for scalability and agility
• DevOps integration for continuous modernization
• API integration to connect legacy systems with modern applications

Company Overview

• Min Project Size: $50,000+
• Hourly Rate: $50 – $99/hr
• Employees: 200 – 499
• Founded: 2010

Endava delivers agile cloud transformation with particular strength in financial services and retail sectors.

Their methodology emphasizes continuous improvement and optimization post-migration, ensuring modernized systems deliver ongoing value.

Key Services

• Mainframe replatforming and cloud migration
• Agile cloud transformation and DevOps enablement
• Continuous improvement and system optimization
• Expertise in finance, retail, and telecom

Company Overview

• Min Project Size: $100,000+
• Hourly Rate: $50 – $99/hr
• Employees: 10,000+
• Founded: 2000

Selecting the best-rated mainframe modernization company for your organization requires evaluating multiple factors beyond just technical capabilities:

• Assess Industry Experience

Does the provider have proven experience in your specific industry? Banking modernization differs significantly from healthcare or government. Look for case studies and references from organizations similar to yours.

• Evaluate Their Modernization Philosophy

Some firms push full cloud migration regardless of fit. Others default to rehosting because it’s easier. The best mainframe software companies tailor strategies to your specific needs, even if that means recommending approaches that aren’t their primary offering.

• Examine Their Automation Capabilities

Manual code conversion is slow and error-prone. Ask about AI-powered analysis tools, automated refactoring platforms, and testing frameworks. Companies investing in automation deliver faster, more reliable results.

• Verify Post-Modernization Support

Modernization isn’t a one-time event. What happens after go-live? The best mainframe modernization companies provide ongoing optimization, performance tuning, and support as you continue evolving your modernized environment.

• Check References and Case Studies

Don’t just read polished case studies—talk to actual clients. Ask about challenges encountered, how the vendor handled problems, and whether they’d choose that partner again.

• Understand Their Team Model

Will you get dedicated experts or a rotating cast of consultants? Continuity matters in complex modernization projects. Understand exactly who will be working on your project and their experience level.

• Review Security and Compliance Practices

Mainframes handle your most sensitive data. Ensure that the top companies for mainframe modernization have appropriate certifications (ISO 27001, SOC 2), follow secure development practices, and understand compliance requirements in your industry.

• Evaluate Cultural Fit

You’ll be working closely with your modernization partner for months or years. Do they communicate clearly? Do they listen? Do they share your values around quality and customer service?

You’ve got hundreds of options when it comes to mainframe service providers. So why should Code District be your top choice for mainframe modernization?

Code District has earned a strong reputation among the top companies for mainframe modernization. The company is known for its affordable services and on-time project delivery.

The company focuses on protecting your data from unauthorized access and corruption during modernization. The ISO 27001 and ISO 9001 certifications testify to their commitment to data security and privacy.

Since its inception in 2017, Code District has grown to 200+ mainframe modernization experts. The team is highly skilled and has extensive experience, so they know the ins and outs of every industry and how to tackle the mainframe modernization challenges.

Ready to modernize your mainframe systems? Request a free consultation to share your needs, get strategic advice on modernization, and learn how it could benefit your business.