IBM AS/400 Users List: Companies Still Using AS/400 and iSeries in 2025

The IBM AS/400 is one of the most durable computing platforms ever built. First released in 1988, it has outlasted dozens of competing systems and continues to power mission-critical operations at 45,000+ companies worldwide. In 2025, organizations running IBM AS/400 — now known as IBM i — represent a concentrated, identifiable, and highly valuable B2B audience.

For vendors selling modernization services, IBM i application development tools, managed services, security solutions, or migration platforms, a verified AS/400 users list is one of the most targeted datasets available. This guide explains what IBM AS/400 is, which companies still use it, and how to build a precise outreach strategy using ELP Data's verified B2B intelligence.

Explore our IBM Users List and IBM Mainframe Users List for related targeting options.

What Is IBM AS/400 / iSeries?

The IBM AS/400 (Application System/400) is a midrange computer system introduced by IBM in June 1988. It was designed for small and medium-sized businesses requiring a reliable, integrated computing environment for business applications. Unlike many systems of its era, the AS/400 combined the operating system, database, and application environment into a single integrated platform — a design decision that made it exceptionally stable and easy to manage.

IBM rebranded the AS/400 platform multiple times over the decades. In 2000, it became the iSeries. In 2006, it was renamed the System i. Since 2008, IBM has marketed the platform as IBM Power Systems running IBM i, though most users and vendors still refer to it colloquially as the AS/400 or iSeries.

The IBM i operating system is object-based, which gives it an unusually clean security and integration model. Applications written for the AS/400 in the 1990s often run without modification on modern IBM Power hardware — a compatibility legacy unmatched in enterprise computing. This backward compatibility is a key reason so many organizations have never seen a compelling reason to migrate away.

The platform supports programming languages including RPG (Report Program Generator), COBOL, CL (Control Language), Java, Python, and Node.js — making it possible for organizations to modernize application layers without replacing the underlying infrastructure.

Which Companies Still Use AS/400?

The AS/400 installed base is concentrated in industries where reliability, transactional throughput, and application stability are non-negotiable. The following sectors account for the majority of active AS/400 deployments:

• Manufacturing — Discrete and process manufacturers use AS/400 and IBM i for production scheduling, inventory control, shop floor management, and ERP applications. Many run IBM i-based ERP platforms such as MAPICS, BAAN, Infor System21, or custom RPG applications built over decades.
• Retail and Distribution — Mid-market retailers and wholesale distributors rely on AS/400 for point-of-sale integration, order management, purchasing, and financial reporting. The platform's ability to handle high transaction volumes with minimal downtime makes it well-suited to retail environments.
• Financial Services and Banking — Community banks, credit unions, insurance companies, and regional financial institutions run core banking and policy administration systems on IBM i. Many of these institutions have customer-facing systems built on AS/400 backends that predate modern web architecture.
• Government and Public Sector — State and local government agencies, particularly in the United States, continue to run AS/400-based systems for licensing, benefits administration, tax processing, and records management. Budget cycles and risk aversion slow replacement timelines significantly.
• Healthcare and Insurance — Healthcare providers and insurance carriers use IBM i for claims processing, billing, patient records, and actuarial systems. Regulatory compliance requirements and the complexity of legacy integrations create strong institutional resistance to platform changes.

Company profiles span the full mid-market range — typically organizations with 100 to 5,000 employees and annual revenues between $10 million and $1 billion. These are substantial businesses with real IT budgets and active vendor relationships.

Why AS/400 Users Are Valuable B2B Targets

The business case for targeting companies using AS/400 is strong across multiple B2B use cases. Here is why this audience commands premium attention from technology vendors and service providers.

Legacy Modernization Is the Defining IT Priority
Every AS/400 organization faces the same strategic question: modernize the existing IBM i platform or migrate to a different architecture entirely. Both paths require significant investment. Vendors offering IBM i modernization tools, RPG-to-web application conversion, modern UI frameworks, cloud hosting for IBM i, and DevOps tooling for IBM i all have a clearly defined and receptive audience in this space.

IBM i Skills Shortage Creates Urgency
The IBM i developer community is aging. RPG programmers and IBM i system administrators who built these platforms in the 1990s are approaching or entering retirement. Organizations face an acute skills shortage — and they are actively investing in training programs, offshore IBM i development teams, managed services, and automation tools to compensate. Any vendor addressing the IBM i talent gap has an immediate and pressing selling proposition.

Cybersecurity and Compliance Exposure
Older IBM i installations often run with minimal security configuration — a legacy of the era when the AS/400 was considered inherently secure. In the current threat environment, this assumption is dangerous. IBM i-specific security tools, vulnerability assessment services, and compliance monitoring solutions are in growing demand across this audience.

Migration Services Demand Is Rising
Organizations that decide to exit the IBM i platform entirely face a significant migration challenge. Decades of RPG code, embedded business logic, and tight database integration make AS/400 migrations among the most technically complex IT projects available. System integrators, migration platform vendors, and consulting firms with IBM i expertise command premium rates and long engagements.

How Many Companies Use AS/400 in 2025?

One of the most common questions in this space — “as400 how many companies use” — has a clear answer based on ELP Data's verified intelligence. ELP Data tracks 45,000+ companies actively running IBM AS/400, iSeries, or IBM i worldwide — a reachable, verified installed base ready for outreach. IBM has historically cited over 100,000 IBM i installations at peak, with the active base declining gradually as organizations migrate or consolidate onto modern platforms.

ELP Data's IBM AS/400 users list includes 90,000+ verified decision-maker contacts across these companies — IT Directors, Systems Administrators, CIOs, and IBM i Developers with verified direct email, phone, and LinkedIn profiles. Every record is verified quarterly to maintain 97% accuracy.

The United States accounts for the largest single country share — estimated at 40–45% of the global AS/400 installed base. Key US concentrations are in the Midwest manufacturing belt, financial services firms in the Northeast, and retail and distribution companies across the South and Central regions.

Outside the US, significant AS/400 populations exist in:

• Germany and the DACH region — Strong manufacturing and Mittelstand presence
• United Kingdom — Financial services, retail, and government
• Canada — Manufacturing, distribution, and financial services
• Australia and New Zealand — Government and healthcare

ELP Data's verified IBM AS/400 users list captures active installations across all major geographies, with verified company and contact records ready for immediate outreach.

How to Reach IBM AS/400 Decision-Makers

Targeting the right contacts within AS/400-using organizations requires understanding the stakeholder map. These environments are often managed by small, specialist IT teams with high institutional knowledge and strong vendor loyalty. The most productive job titles to target include:

• IBM i Systems Administrator / AS/400 Administrator — The technical gatekeeper. This person manages the platform day-to-day and is the primary evaluator for any tool or service that touches IBM i.
• IT Director / IT Manager — Owns the overall technology strategy and budget. Often the decision-maker for larger modernization or managed services contracts.
• CIO / VP of IT — Involved in strategic decisions around platform modernization, cloud strategy, and multi-year technology investment planning.
• Application Development Manager — Responsible for the RPG, COBOL, and CL codebase. Key stakeholder for modernization tools, DevOps platforms, and developer training programs.
• CFO / Finance Director — Financial systems on IBM i often have direct CFO visibility. Investment decisions for ERP modernization or platform migration require finance leadership sign-off.
• Operations Director / VP Operations — Business process owner for manufacturing, distribution, or operational systems running on IBM i.

ELP Data's AS/400 users list includes verified direct emails, phone numbers, LinkedIn profiles, and firmographic data for decision-makers within IBM AS/400 and IBM i-using organizations. All records are verified for accuracy and compliance — no manual data cleaning required before outreach.

Filtering options include industry vertical, geography, company size, revenue range, and job function — enabling targeted account-based marketing campaigns or broad market awareness programs. Our data integrates directly with Salesforce, HubSpot, and all major CRM platforms. Explore our IBM Users List for the full picture of IBM technology coverage.