CDISC opened public review for SENDIG v4.0 in April 2026, with publication targeted for Q4 2026. While the FDA has not yet announced an implementation timeline, many CROs and sponsors are watching from a distance.
That posture has a cost.
SENDIG v4.0 isn’t just another version update. It introduces some of the most significant structural changes since its original release. The changes extend far beyond routine version updates, introducing structural enhancements. Most notably, the retirement of Supplemental Qualifiers a change that will require more than a simple configuration update. These updates have implications for: Data collection, Dataset design, Validation, Submission workflows
Here is what you need to know right now.
1. Nine New Domains Are Being Added: Eight Scientific, One Structural
Previous versions of SEND had no standard way to represent certain study types, which forced teams to build custom domains as workarounds. SENDIG v4.0 addresses these gaps by providing standardized domain models, making submissions more consistent, and reducing the need for custom implementations.
Eight of these address scientific areas while the ninth introduces a new structural approach for handling non-standard variables
- Genetic Toxicology In Vivo (GV)
- Cell Phenotyping (CP)
- Immunogenicity Specimen Assessments (IS)
- Ophthalmic Examinations (OE)
- Nervous System Tests (NV)
- Skin Test Results (SK)
- Pharmacokinetics Input (PI)
- Scoring Scales (SX)
The ninth addition,
- NS– (Non-Standard Variables), a structural domain that introduces a new structural mechanism that replaces Supplemental Qualifiers.
If your organization is using custom domains in any of these scientific areas, those workarounds are likely to become technical debt under SENDIG v4.0. Assessing and mapping your current structures to the new standard now will be far less disruptive than waiting for an FDA implementation deadline.
2. Supplemental Qualifiers Are Gone. NS– Takes Their Place.
This is the change most organizations aren’t talking about yet, and it’s the one that will require the most work.
SUPP– (Supplemental Qualifiers) has been deprecated and removed from SENDIG v4.0, along with all references to it in the implementation guide. CDISC has introduced NS– (Non-Standard Variables) as the replacement domain, a dedicated relationship domain that handles non-standard variables without the structural overhead SUPP– required.
This is not a domain swap. It is a structural change to how non-standard data is represented across the entire standard. If your validation engine, define.xml generation, or internal QC processes are built around the SUPP– mechanism, that logic breaks under v4.0.
Auditing where SUPP– lives in your current pipeline is a practical, near-term action that does not require waiting for an FDA requirement date.
3. TF and BG Are Also Deprecated
Two existing SEND domains are also being removed from SENDIG v4.0: Tumor Findings (TF) and Body Weight Gains (BG). These have been flagged for some time, so this should not be a surprise. If you have not already mapped how your data collection and reporting processes will handle this transition, now is a good time to do that.
4. Conformance Language Is Getting Stricter, and the Numbers Reflect It
Throughout SENDIG v4.0, CDISC has replaced “should” and “should not” with “must” and “must not” wherever the text was intended to support a conformance rule.
This shift is not just linguistic, the scale of this shift is significant: SENDIG v4.0 introduces 463 new conformance rules while deprecating 142 from previous versions. Items that were previously treated as recommendations may now be interpreted as mandatory. Which means some findings that may have passed validation previously could be flagged going forward. If your SEND team treats “should” language as optional guidance today, that assumption is worth revisiting before v4.0 becomes a requirement.
5. The Tables and Appendices Have Been Rebuilt
The domain specification tables have been restructured to align with SDTM v3.0, and three new appendices have been added: Define-XML, Trial Summary and Trial Set Codes, and a SEND Scope appendix.
For teams building or maintaining SEND tooling, the updated specification tables introduce changes to column structure and naming conventions that directly affect how tables are parsed, mapped, and integrated into validation and automation workflows.
The Timeline, in Plain Terms
CDISC publishes the standard. FDA decides when it is required. Those two events are typically separated by a year or more. Per CDISC’s own public review webinar in March 2026, publication is targeted for Q4 2026. There is no FDA requirement date yet, and existing submissions should continue using SENDIG v3.1.1 until FDA announces otherwise.
What that gap means in practice: the work of understanding v4.0, auditing your current pipelines, and making incremental decisions about readiness should happen in that window. Organizations that wait for an FDA deadline to begin that work will have less time and more pressure than those that start now.
FAQ
Does SENDIG v4.0 affect studies that have already started?
No. Studies are governed by the SENDIG version required as of their study start date. Until FDA sets a requirement date for v4.0, active studies continue under SENDIG v3.1.1.
When will the FDA require SENDIG v4.0?
The FDA has not announced a requirement date. That announcement, when it comes, will appear in the FDA Data Standards Catalog.
Where can I read the full v4.0 public review materials?
Directly at cdisc.org/public-review/sendig-v4-0.