Mainframe Modernization Companies
A neutral market map of companies delivering mainframe modernization, plotted by modernization approach and supplier layer. Alphabetical, never ranked or scored; paid Featured placements are labeled and do not change the ordering.
Compare mainframe modernization companies
Filter by what a company migrates from, its modernization approach, supplier type, team size, or region. Listed alphabetically — never ranked, scored, or rated. “Featured” is a labeled paid slot and does not change the ordering.
| Company | Approach | Type | Team size | Region | |
|---|---|---|---|---|---|
| Accenture | Replatform | Agency | Enterprise | Global | 1 documented source |
| Advanced | Refactor | Agency | — | — | 1 documented source |
| Astadia | ReplatformRefactor | Agency | Mid-size | Global (US HQ) | 4 documented sources |
| AWS Mainframe Modernization | Refactor | Platform | Enterprise | Global | 1 documented source |
| Azure Migrate | RehostReplatform | Platform | — | — | 0 documented sources |
| Capgemini | ReplatformRefactor | Agency | Enterprise | Global (France HQ) | 2 documented sources |
| CloudFrame | Refactor | Agency | — | — | 1 documented source |
| Cognizant | ReplatformRefactor | Agency | Enterprise | Global (US HQ) | 4 documented sources |
| Deloitte | Replatform | Agency | Enterprise | Global | 2 documented sources |
| DXC Technology | RehostReplatformRetain & optimize | Agency | Enterprise | Global | 1 documented source |
| Heirloom Computing | RehostReplatform | Agency | Boutique | USA | 1 documented source |
| IBM Consulting | Refactor | Agency | Enterprise | Global | 3 documented sources |
| IBM watsonx Code Assistant for Z | Refactor | Platform | — | — | 0 documented sources |
| Infosys | ReplatformRefactor | Agency | Enterprise | Global (India HQ) | 4 documented sources |
| Intellias | Refactor | Agency | Enterprise | Ukraine (Global) | 1 documented source |
| Kyndryl | ReplatformRetain & optimize | Agency | Enterprise | Global | 1 documented source |
| Micro Focus | ReplatformRefactorRetain & optimize | Platform | Enterprise | Global | 1 documented source |
| Modern Systems (Rocket Software) | RehostReplatformRefactor | Platform | Enterprise | USA | 1 documented source |
| Scalo | Refactor | Agency | Mid-size | Poland (Global) | 1 documented source |
| SoftServe | ReplatformRefactor | Agency | Enterprise | Global (Ukraine Origins) | 2 documented sources |
| TCS | ReplatformRefactor | Agency | Enterprise | Global (India HQ) | 5 documented sources |
| TSRI | Refactor | Agency | Boutique | USA | 1 documented source |
“Documented evidence” counts the migration paths and services in this domain where we hold a relationship record for that company — each one links to the page it came from, under the company’s entry below.
Approach matrix
How Mainframe Modernization companies map to modernization approach
Rows group mainframe modernization companies by modernization approach, defined in our 7 Rs of application modernization framework; columns separate product vendors from delivery firms.
| Approach | Product | Delivery firm |
|---|---|---|
| Rehostsame code, new infrastructure or emulator | Product | Delivery firm |
| Replatformsame core code, swapped runtime or managed services | Product | Delivery firm |
| Refactorthe existing code is converted or restructured in place | Product | Delivery firm |
| Rewriterebuilt from scratch on a new architecture | ProductNone documented | Delivery firmNone documented |
| Replaceswapped for a commercial or SaaS product | ProductNone documented | Delivery firmNone documented |
| Retain & optimizekept in place and improved | Product | Delivery firm |
What each company delivers in mainframe modernization
One entry per company, carrying only attributes we can point at a source for. Where a company has no published evidence for an attribute, nothing is shown rather than a placeholder.
Engagement bands in this domain
- Small
- $80K–$150K
- Mid-market
- $180K–$350K
- Enterprise
- $400K–$800K
Spans are the published pricing tiers on this domain’s service pages (COBOL Migration Services), cross-checked against the cost benchmarks. A company is placed in a band by its team size — this is a statement about the size of engagement firms of that scale typically deliver here, not a rate card. We publish no per-vendor rates.
Accenture
AgencyStrategic modernization programs at execution scale, with the myNav platform used to select a migration path across all major cloud providers.
Replatform- Best for
- Strategic modernization programs
- Modernizes
- Mainframe (z/OS) to AWS, Azure, GCP
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- Mainframe to Azure Migration Services
Advanced
AgencyCOBOL rehosting and refactoring onto C#/.NET, with documented strength in complex legacy databases such as IDMS and Datacom rather than straightforward file-based systems.
Refactor- Best for
- Complex legacy databases (IDMS, Datacom)
- Modernizes
- COBOL to .NET
- Documented in
- COBOL to C# Migration Services
Astadia
AgencyPure-play mainframe migration specialist; the FastTrack platform automates code refactoring for IBM and Unisys estates, with documented 99.9% functional equivalence on COBOL-to-C# work.
ReplatformRefactor- Best for
- Fast replatforming to AWS/Azure
- Modernizes
- COBOL, Unisys, Mainframe (z/OS) to AWS, Azure, .NET, Java
- Firm profile
- Mid-size · Global (US HQ)
- Typical engagement band
- Mid-market · $180K–$350K
AWS Mainframe Modernization
PlatformAWS-run tooling and infrastructure for mainframe workloads, including the Blu Age toolchain for automated COBOL, PL/I, and RPG conversion to Java.
Refactor- Best for
- COBOL to Java automated conversion
- Modernizes
- COBOL, PL/I, RPG to AWS
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- COBOL Migration Services
Azure Migrate
PlatformMainframe workload assessment and Azure landing-zone sizing — a discovery and planning step, not a code-conversion tool.
RehostReplatform- Modernizes to
- Azure
Capgemini
AgencyIndustrial-scale modernization under an Economic Application Modernization approach that optimizes run cost while migrating, including large AS/400-resident ERPs such as JD Edwards.
ReplatformRefactor- Best for
- Large ERPs running on AS400 (JD Edwards, etc.)
- Modernizes
- RPG, IBM i (AS/400), COBOL to AWS, Azure, .NET
- Firm profile
- Enterprise · Global (France HQ)
- Typical engagement band
- Enterprise · $400K–$800K
CloudFrame
AgencyAutomated COBOL-to-Java or C# cross-compilation aimed at cutting MIPS-based mainframe billing, positioned as a lower-risk bridge step rather than a full platform exit.
Refactor- Best for
- Reducing MIPS costs immediately
- Modernizes
- COBOL to .NET
- Documented in
- COBOL to C# Migration Services
Cognizant
AgencyThe Skygrade platform applies generative AI to accelerate cloud-native transformation, with the firm's deepest mainframe delivery evidence in banking, healthcare, and life sciences.
ReplatformRefactor- Best for
- Healthcare and regulated industries
- Modernizes
- RPG, IBM i (AS/400), Mainframe (z/OS) to AWS, Azure
- Compliance & regulated delivery
- Banking, Healthcare, Life sciences
- Firm profile
- Enterprise · Global (US HQ)
- Typical engagement band
- Enterprise · $400K–$800K
Deloitte
AgencyEnterprise transformation that runs risk, controls, and compliance advisory alongside the conversion — its mainframe delivery evidence sits on IBM i (AS/400) and RPG estates moving to AWS and Azure.
Replatform- Best for
- Regulated organizations needing governance and audit rigor alongside the migration
- Modernizes
- RPG, IBM i (AS/400) to AWS, Azure
- Compliance & regulated delivery
- Regulated industries (governance and audit advisory)
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
DXC Technology
AgencyMainframe-as-a-Service and hybrid modernization built on CSC and HPE Enterprise Services heritage, aimed at estates that optimize on-premise while moving in stages.
RehostReplatformRetain & optimize- Best for
- Risk-averse organizations needing 'safe hands'
- Modernizes
- Mainframe (z/OS) to AWS
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- Mainframe to AWS Migration Services
Heirloom Computing
AgencyAutomated refactoring of COBOL and CICS applications to Java, delivered as a PaaS that runs the converted workload on AWS.
RehostReplatform- Best for
- Rehosting/Replatforming with minimal code change
- Modernizes
- COBOL, CICS, Mainframe (z/OS) to AWS
- Firm profile
- Boutique · USA
- Typical engagement band
- Small · $80K–$150K
- Documented in
- Mainframe to AWS Migration Services
IBM Consulting
AgencyIBM Z modernization from the platform's originator, using watsonx Code Assistant for Z to translate COBOL to Java — strongest fit for estates staying in the IBM ecosystem or moving to hybrid cloud.
Refactor- Best for
- Staying within IBM ecosystem
- Modernizes
- COBOL to IBM Z, IBM hybrid cloud, .NET, Java
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
IBM watsonx Code Assistant for Z
PlatformCOBOL understanding, documentation generation, and assisted Java refactoring; usable for code comprehension before any platform exit is committed.
Refactor- Modernizes from
- COBOL
Infosys
AgencyThe Cobalt suite covers mainframe and automated AS/400 modernization as a managed service, aimed at risk-averse enterprises that want the program run for them.
ReplatformRefactor- Best for
- Comprehensive managed services
- Modernizes
- COBOL, RPG, IBM i (AS/400), Mainframe (z/OS) to AWS, Azure
- Firm profile
- Enterprise · Global (India HQ)
- Typical engagement band
- Enterprise · $400K–$800K
Intellias
AgencyAutomated COBOL parsing with documented 98% accuracy on large codebases — positioned for 500k+ LOC estates with dense business logic.
Refactor- Best for
- Large codebases (500k+ LOC) with complex business logic
- Modernizes
- COBOL to Java
- Firm profile
- Enterprise · Ukraine (Global)
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- COBOL to Java Migration Services
Kyndryl
AgencyThe largest IT infrastructure services provider, spun off from IBM; its mainframe practice is built around optimize-and-coexist and managed IBM i operations rather than a forced exit.
ReplatformRetain & optimize- Best for
- Operational stability during transition
- Modernizes
- RPG, IBM i (AS/400) to AWS, Azure
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- AS/400 to Cloud Migration Services
Micro Focus
PlatformThe tooling layer many other vendors' migrations run on: Visual COBOL executes COBOL on .NET and the JVM, and Enterprise Analyzer is the reference tool for legacy code assessment.
ReplatformRefactorRetain & optimize- Best for
- Hybrid modernization approaches
- Modernizes
- COBOL to .NET, JVM
- Firm profile
- Enterprise · Global
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- COBOL Migration Services
Modern Systems (Rocket Software)
PlatformReplatforming and emulation that move legacy workloads onto x86 without rewriting the COBOL, now delivered under Rocket Software.
RehostReplatformRefactor- Best for
- Keep COBOL code, run on x86
- Modernizes
- COBOL to x86
- Firm profile
- Enterprise · USA
- Typical engagement band
- Enterprise · $400K–$800K
- Documented in
- COBOL Migration Services
Scalo
AgencyLegacy modernization and cloud migration for regulated financial services, with documented COMP-3 packed-decimal handling and audit-trail delivery.
Refactor- Best for
- Regulated industries requiring audit trails
- Modernizes
- COBOL to Java
- Compliance & regulated delivery
- SOC 2, HIPAA, Financial services
- Data & integration
- Documented COMP-3 packed-decimal handling — the field-precision problem that breaks mainframe-to-relational data conversion.
- Firm profile
- Mid-size · Poland (Global)
- Typical engagement band
- Mid-market · $180K–$350K
- Documented in
- COBOL to Java Migration Services
SoftServe
AgencyThe SoftServe Application Modernization Platform gives a repeatable framework for moving workloads to AWS and Azure, with the firm's strongest verticals in healthcare and retail.
ReplatformRefactor- Best for
- Refactoring to microservices
- Modernizes
- Mainframe (z/OS) to AWS, Azure
- Compliance & regulated delivery
- Healthcare
- Firm profile
- Enterprise · Global (Ukraine Origins)
- Typical engagement band
- Enterprise · $400K–$800K
TCS
AgencyThe MasterCraft suite applies intelligent automation to legacy conversion at scale — currently migrating over 50 million lines of COBOL to Java for a single financial-services client.
ReplatformRefactor- Best for
- Large-scale enterprise migrations
- Modernizes
- COBOL, RPG, IBM i (AS/400), Mainframe (z/OS) to AWS, Azure, Java
- Compliance & regulated delivery
- Banking, Insurance
- Firm profile
- Enterprise · Global (India HQ)
- Typical engagement band
- Enterprise · $400K–$800K
TSRI
AgencyJANUS Studio reaches near-total automation on rare source languages as well as COBOL, with the firm's delivery record concentrated in defense and government systems.
Refactor- Best for
- Defense and highly regulated government sectors
- Modernizes
- COBOL, Ada, Fortran, Jovial to .NET
- Compliance & regulated delivery
- Defense, Government
- Firm profile
- Boutique · USA
- Typical engagement band
- Small · $80K–$150K
- Documented in
- COBOL to C# Migration Services
Which mainframe modernization companies are recognized for their security?
This page publishes named compliance evidence, never a security score. Scalo documents SOC 2 and HIPAA delivery in financial services. Deloitte runs risk, controls, and compliance advisory alongside the conversion. TSRI's record is concentrated in defense and government, TCS in banking and insurance, Cognizant in banking, healthcare, and life sciences.
For COBOL modernization services, which companies have the best expertise?
Expertise here means documented source-language coverage, not a rating we assign. TSRI handles Ada, Fortran, and Jovial alongside COBOL. AWS Mainframe Modernization adds PL/I and RPG. Astadia covers Unisys as well as IBM estates, and Heirloom Computing covers CICS. Filter the comparison above by the languages actually in your estate.
Which companies in mainframe modernization are underrated?
We do not rank, so no company here is rated or underrated. The question usually means the specialists rather than the global integrators: Astadia, Heirloom Computing, Scalo, and TSRI run pure-play mainframe practices, and the comparison table's team-size filter isolates the boutique and mid-size firms on this page.
Which IBM i modernization tools are best for a $50k budget?
No engagement band published for this domain starts at $50,000. The smallest, $80K–$150K, covers a single COBOL application under 50k lines. A budget at that level buys assessment, inventory, and dependency mapping rather than conversion — the cost benchmarks show what each band actually delivers.
Market map
Companies to evaluate for Mainframe Modernization
Scope: published mainframe modernization companies with documented category, migration-path, or service evidence in this research domain.
Last evaluated
208
Published modernization companies reviewed
22
Companies shown for mainframe modernization
Inclusion criteria: A company must have a published profile and documented category, migration-path, or service evidence in this domain. See the evidence threshold in our research methodology.
How to choose: Start with documented buyer fit (20 profiles) and specialty evidence (22), then narrow by team size (18) and location (18). Open a profile to verify the underlying experience before shortlisting.
This is an alphabetical market map, not an ordinal ranking. Paid Featured placements are labeled and do not imply a recommendation.
Mainframe modernization has two supplier layers: platforms and tools support discovery, automated transformation, emulation, integration, testing, or cloud execution; delivery firms supply COBOL and PL/I expertise, target architecture, data migration, validation, and long-running program governance. Evaluate tools by source-language coverage, conversion transparency, runtime dependency, and test evidence. Evaluate delivery firms by workload-scale experience, retained mainframe knowledge, target-platform capability, delivery capacity, and comparable outcomes. Companies appear alphabetically because the best fit depends on the chosen modernization path. The data layer is where these engagements are won or lost, and it is scoped separately from the code. VSAM, IMS, and DB2 records carry EBCDIC encoding and COMP-3 packed-decimal fields that have no direct equivalent in a relational target, so a firm's mainframe data modernization capability — schema conversion, encoding and precision handling, and reconciliation against the source — is a distinct question from whether it can convert COBOL. Ask for both separately.