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GRID (Global Registration Identifier for Donors)

In alignment with the World Marrow Donor Association (WMDA), the NMDPSM uses GRID as the donor identifier. Whenever possible, to copy and paste the GRID from a source of truth instead of risking error due to manual entry.

What is GRID?

The GRID standard is a 19-character identifier composed of three elements:

  1. A 4-digit Issuing Organization Number (ION) – (NMDP) ION is 3553
  2. A 13-character Registration Donor Identifier (RDI) assigned by the issuing organization
  3. A 2-digit checksum – a calculated number that ensures the preceding 17 digits are accurate and not mistyped
Global Registration Identified for Donors

*other registries may have capitalized alpha characters in their GRID

Assignment of GRIDs

NMDPSM assigns a GRID to all donors on the NMDP Registry.

We will follow and promote the GRID Standard as published by ICCBBA and additional implementation details as provided by WMDA. See this ICCBBA webpage for details.

Systems & Sources of Truth for traceability and validation

  • AC/CCs: Donor Tracking Sheet
  • DCs: STAR Link Web
  • TCs: MatchSource®


  • NMDP product labels utilize GRID as the identifier on the product.
    • NMDP system-generated blood sample labels display GRID. Sample labels include verification/CT, IDM and donor workup/collection samples.


Please check our GRID FAQ document above. You can use Ctrl+F to search for a keyword in the document.

If you still have questions, please reach out to your NMDP contact.