SharePoint 2016/2019 End-of-Support Migration Plan

Organizations still running SharePoint Server 2016 or 2019 should treat migration planning as more than a hosting upgrade. The real work is deciding what to move, what to modernize, what to archive, and what governance model will keep SharePoint Online healthy after go-live.

Waiting until the deadline is close usually increases risk. Legacy farms often contain abandoned sites, customizations, oversized libraries, InfoPath forms, Nintex workflows, SharePoint Designer workflows, service accounts, and permissions exceptions that are easy to underestimate.

Start with inventory

A useful inventory includes:

• Farms, servers, patch levels, web applications, content databases, and site collections
• Storage volume, list and library complexity, file counts, large files, and path issues
• Site owners, business owners, last activity, and criticality
• InfoPath forms, Nintex workflows, SharePoint Designer workflows, custom scripts, timer jobs, and integrations
• Permissions, broken inheritance, external sharing, service accounts, and orphaned users
• Records, retention, sensitive information, and legal hold requirements

Inventory is not just a technical step. It is how you discover the business processes hidden inside the farm.

Separate content by decision

Do not migrate everything by default. Classify each site or library into a decision category:

• Migrate active collaboration content into SharePoint Online or Teams-connected sites.
• Modernize forms, workflows, pages, lists, and processes that need redesign.
• Archive records or low-change content that should not become active collaboration content.
• Retire abandoned sites, duplicate libraries, and obsolete processes.
• Hold regulated or legally sensitive content until stakeholders approve the target.

Validate the target tenant

SharePoint Online migration should align with the broader Microsoft 365 operating model. Confirm:

• Identity, Entra ID groups, Conditional Access, and external sharing policies
• Teams architecture and site ownership
• OneDrive migration strategy
• Sensitivity labels, retention labels, and DLP policies
• Search, hub sites, metadata, and navigation
• Power Platform environment strategy for forms and workflows
• Help desk and support processes after cutover

Pilot before broad waves

Pilot representative sites before moving the entire estate. Include simple team sites, high-volume libraries, complex permissions, workflows, forms, pages, and regulated content.

Validate:

• Content counts and metadata
• Permissions and group membership
• Links, pages, navigation, and search
• Workflow and form dependencies
• Sync behavior and user access
• Business process outcomes, not only migration tool success counts

Plan hypercare

The migration is not finished when data lands. Schedule hypercare, owner support, help desk scripts, governance cleanup, adoption messages, and admin handover.

A post-migration backlog should capture:

• Permission cleanup
• Owner gaps
• Broken links
• Workflow failures
• Legacy forms requiring modernization
• Retention and sharing policy issues
• Training and adoption needs

Recommended next step

Start with a Microsoft Migration Readiness Assessment or the SharePoint 2016/2019 End-of-Support Migration service page. If your farm includes InfoPath or Nintex, include Form Migrator and Flow Migrator in the discovery plan.