diff --git a/CHANGELOG.md b/CHANGELOG.md
index 71cf7ca..f62957d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.4.0] - 2026-10-14
+
 This release aligns the library with Bishop's VAS documentation manual dated 10-12-2026 and
 reproduces his VAS runs of October 2026 (PM SDS, PM INERT, known-effects and Medicare decks).
 Equation numbers below are that manual's.
@@ -1112,7 +1114,8 @@ and may change between minor versions until 1.0.
 - `natsort >= 8.0`
 - `plotly >= 5.18, < 7`
 
-[Unreleased]: https://github.com/cnicholas/processbehavior/compare/v0.3.3...HEAD
+[Unreleased]: https://github.com/cnicholas/processbehavior/compare/v0.4.0...HEAD
+[0.4.0]: https://github.com/cnicholas/processbehavior/compare/v0.3.3...v0.4.0
 [0.3.3]: https://github.com/cnicholas/processbehavior/compare/v0.3.2...v0.3.3
 [0.3.2]: https://github.com/cnicholas/processbehavior/compare/v0.3.1...v0.3.2
 [0.3.1]: https://github.com/cnicholas/processbehavior/compare/v0.3.0...v0.3.1
diff --git a/docs/reference/validation.md b/docs/reference/validation.md
index 081e126..77af8e1 100644
--- a/docs/reference/validation.md
+++ b/docs/reference/validation.md
@@ -8,7 +8,7 @@ and the run fails if any of them disagree.
 
 **1547 assertions pass**, 0 fail, 4 have no reference value yet.
 
-Generated by `validation/e2e_bishop_report.py` from processbehavior 0.3.3.
+Generated by `validation/e2e_bishop_report.py` from processbehavior 0.4.0.
 
 ## Coverage
 
diff --git a/processbehavior/__init__.py b/processbehavior/__init__.py
index 843246c..f4776db 100644
--- a/processbehavior/__init__.py
+++ b/processbehavior/__init__.py
@@ -47,7 +47,7 @@
 prefix (e.g. ``sds_detector.py``); the model itself is three-state.
 """
 
-__version__ = '0.3.3'
+__version__ = '0.4.0'
 
 # Result object
 from processbehavior.analysis_result import AnalysisResult