https://powerofus.force.com/s/article/NPSP-BP-Getting -Started-Program-Management#week4

When migrating client and program data to the Program Management Module (PMM) in NPSP, it is important to use the appropriate tools for data import and deduplication to ensure data integrity and avoid duplication. The NPSP Data Importer is specifically designed for importing client information, including deduplication against existing records. The Data Import Wizard can be used for uploading program data, which may not require the same level of deduplication as client data.

Steps:

Prepare the client data, ensuring all necessary fields are included and formatted correctly.

Use the NPSP Data Importer to upload the client information, which includes built-in deduplication features to match against existing records.

Prepare the program data similarly, ensuring proper formatting and completeness.

Use the Data Import Wizard to upload the program data. This tool is suitable for handling bulk data uploads and does not inherently include deduplication, which is less critical for program data compared to client data.