What are the Top Application Modernization Companies in the United States 2026-2027?
Companies migrating legacy applications to modern architectures, languages and cloud platforms. Compare verified providers in the United States, see typical 2026-2027 pricing and use our checklist to pick the right partner.
Companies based in the United States only: established software and technology firms based in the United States selected by the iCreativez research team. International providers are shown separately below and are not counted as local.
Companies based in the United States
- 1
Cognizant
Teaneck, New Jersey, United States
Why listed: established firm with an office in the United States, selected by the iCreativez research team for its scale and track record.
- 2
EPAM Systems
Newtown, Pennsylvania, United States
Why listed: established firm with an office in the United States, selected by the iCreativez research team for its scale and track record.
- 3
Thoughtworks
Chicago, United States
Why listed: established firm with an office in the United States, selected by the iCreativez research team for its scale and track record.
- 4
Slalom
Seattle, United States
Why listed: established firm with an office in the United States, selected by the iCreativez research team for its scale and track record.
- 5
Saritasa
Irvine, California, United States
Why listed: established firm with an office in the United States, selected by the iCreativez research team for its scale and track record.
International firms to consider for the United States
Headquartered outside the United States or working remotely, so not counted in the local list above. Some work with clients in the United States through regional offices, partners or remote teams; check coverage before you shortlist.
- 6
Accenture
Headquarters: Dublin, Ireland
Why listed: Established API Development & Modernization firm operating internationally.
- 7
Globant
Headquarters: Luxembourg
Why listed: Established API Development & Modernization firm operating internationally.
- 8
Tata Consultancy Services (TCS)
Headquarters: Mumbai, India
Why listed: Established API Development & Modernization firm operating internationally.
- 9
Infosys
Headquarters: Bengaluru, India
Why listed: Established API Development & Modernization firm operating internationally.
About Application Modernization providers
Companies migrating legacy applications to modern architectures, languages and cloud platforms.
API developers and modernisation specialists connect systems and bring legacy software up to date. Clean interfaces and careful migration planning reduce risk for everything built on top.
In the United States, Application Modernization Companies are concentrated around New York, San Francisco, Los Angeles, Austin, Chicago and Miami. Local rates sit at the upper end of the global ranges, so many buyers in the United States pair a local lead with nearshore or offshore delivery to manage cost.
How to choose the best Application Modernization Companies in 2026-2027
- Ask for phased migration plans with rollback options.
- Ask for API documentation they've written.
- Check versioning, security and rate-limiting practices.
- For modernisation, ask how they keep the old system running during migration.
What does it cost?
API integration projects commonly cost $10,000-$80,000; large modernisation programmes can run from $100,000 to several million.
Before you sign
Ask for a written proposal with scope, milestones, team members and exit terms, and speak to at least one current client of each shortlisted provider.
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Frequently asked questions
What are the top Application Modernization Companies in 2026-2027?
Our 2026-2027 shortlist of Application Modernization Companies includes verified providers such as TechAhead, Unicrew, Trigent Software, Accenture, EPAM Systems. Use the country selector to see only firms based in your country.
What do Application Modernization Companies do?
Companies migrating legacy applications to modern architectures, languages and cloud platforms. API developers and modernisation specialists connect systems and bring legacy software up to date.
How much do Application Modernization services cost in 2026-2027?
API integration projects commonly cost $10,000-$80,000; large modernisation programmes can run from $100,000 to several million. Prices vary by scope, seniority and location, so ask at least three providers for written proposals.
How do I choose the right Application Modernization Company?
Ask for phased migration plans with rollback options. Ask for API documentation they've written. Check versioning, security and rate-limiting practices.
How were these Application Modernization Companies selected?
The worldwide view lists Clutch-verified specialists (registered businesses independently verified on Clutch with working websites, ordered by verified client reviews as of November 2026) and established industry leaders. When you choose a country, the main list shows only companies based in that country or with an office there: Clutch-verified firms with a local office, plus established local firms selected by the iCreativez research team. International firms are shown in a separate, labelled section. Inclusion is free and not paid for.
How this list is compiled
Worldwide view: Clutch-verified specialists (registered businesses independently verified on Clutch with a working website, ordered by their number of verified client reviews) followed by established industry leaders. Country view: the main list is strictly local. It shows only Clutch-verified firms with an office in the selected country and established firms based in that country that the iCreativez research team selected for their scale and track record. Large international firms and remote teams that serve the country appear in a separate, labelled section and are never counted as local. Where we have not yet verified enough local firms, the page says so instead of padding the list. Minimum project size, hourly rates and team size are as published by each company in November 2026. Inclusion is free and not paid for. Providers can request a review via our contact page.