COBOL upgrade portal

Why upgrade

Learn how upgrading to IBM Enterprise COBOL for z/OS 6 helps maximize your IBM Z hardware

Enterprise COBOL support lifecycle

Find support lifecycle information and announcement letters for all Enterprise COBOL versions

COBOL compiler versions, required runtimes, and support information

Find support information for all COBOL versions

What's new in Enterprise COBOL 6.5

Learn about the newest features of IBM Enterprise COBOL 6.5

Changes with Enterprise COBOL 5 and 6

Learn about the differences between previous compilers and Enterprise COBOL 5 and 6

IBM COBOL Upgrade Advisor for z/OS (CUAZ)

Accelerate and simplify your upgrade to Enterprise COBOL 6

IBM COBOL Upgrade Advisor for z/OS (CUAZ) accelerates and simplifies the upgrade to Enterprise COBOL 6 with analysis and reporting in a modern Visual Studio Code (VS Code) interface. CUAZ helps enterprises modernize COBOL applications, reduce upgrade complexity, and stay current with supported compilers while optimizing performance on IBM Z hardware.

Man working on laptop with an overlay of screens from IBM COBOL Upgrade Advisor for z/OS

CUAZ product page

CUAZ interactive demo

CUAZ documentation

CUAZ Ideas portal

How to upgrade

Find upgrade information for current versions of Enterprise COBOL 6

Blog: Prepare to upgrade to Enterprise COBOL for z/OS 6

COBOL 6.5 Migration guide

COBOL 6.4 Migration guide

COBOL 6.3 Migration guide

Migration webinar

Program temporary fixes (PTFs)

Migration FAQs

Performance tuning

These resources help you maximize performance once the upgrade is complete

COBOL 6.5 Performance tuning guide

COBOL 6.4 Performance tuning guide

COBOL 6.3 Performance tuning guide

Performance tuning webinar

COBOL performance tools

Optimize your COBOL programs with the help of these tools

IBM Automatic Binary Optimizer for z/OS

Optimize COBOL performance without recompilation, source code migration or performance tuning

Go to the product page

Automatic Binary Optimizer and COBOL FAQs

Learn how Automatic Binary Optimizer is related to Enterprise COBOL

Go to the FAQs

IBM watsonx Code Assistant for Z Optimize

Enhance the quality and performance of COBOL applications using tailored recommendations

Go to the product page

IBM watsonx Code Assistant for Z Optimize documentation

Learn more about how Z Code Optimization Advice works

Go to the documentation

COBOL testing and conversion tools

Pair your upgrade with tools that boost modernization

IBM Test Accelerator for Z

A test automation and test generation framework with support for on-demand virtual dev and test z/OS environments

COBOL and CICS Command Level Conversion Aid for z/OS (CCCA)

Converts CICS and non-CICS COBOL source programs and copybooks from 68 COBOL Standard and 74 COBOL Standard languages to the 85 COBOL Standard language

IBM watsonx Code Assistant for Z Understand

Understand the implications of any source code changes that may need to be made

Customer success stories

Learn from our world-class clients about the benefits of upgrading

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CIBC

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DATEV

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A large North American bank

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A large North American insurance provider

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More resources

IBM COBOL community

IBM Enterprise COBOL for z/OS product page

IBM Enterprise COBOL for z/OS support library