How much does it cost to replace legacy software?

Legacy software replacement cost is driven by four variables: what you are replacing, what you are replacing it with, how much data must be migrated, and how many systems it integrates with.

Cost by Replacement Type

• Custom rebuild -- $150,000-$400,000. Full replacement built specifically for your workflow. Highest upfront cost, best long-term fit, ability to add AI features natively. Timeline: 6-12 months.
• SaaS platform migration -- $75,000-$200,000. Migrate to an off-the-shelf platform (Salesforce, NetSuite, ServiceNow, etc.). Lower build cost but higher ongoing licensing. Timeline: 3-6 months for implementation and migration.
• Re-platform (existing codebase) -- $50,000-$150,000. Modernize the existing system on a new technology stack. Preserves institutional logic, reduces risk. Timeline: 3-5 months.

Hidden Costs to Budget For

• Data migration and cleanup -- often $10,000-$50,000 depending on data quality
• Integration rebuild -- $5,000-$30,000 per system integration that must be re-implemented
• Staff retraining -- $5,000-$20,000 for change management and documentation
• Parallel running period -- the old and new systems running simultaneously during cutover

Comparing to Maintenance Cost

Legacy systems often cost $30,000-$100,000 per year in maintenance -- patching, workarounds, consultant fees for end-of-life systems, and productivity loss. A $200,000 replacement that eliminates $75,000 in annual maintenance pays back in under 3 years. Code and Trust's legacy modernization practice produces a written cost comparison before any build work begins. Contact us to scope yours.