diff --git a/.github/ISSUE_TEMPLATE/bug_report.yml b/.github/ISSUE_TEMPLATE/bug_report.yml
index a34fa15..33a2c04 100644
--- a/.github/ISSUE_TEMPLATE/bug_report.yml
+++ b/.github/ISSUE_TEMPLATE/bug_report.yml
@@ -85,6 +85,7 @@ body:
       label: Drux version
       description: Which version of Drux are you using?
       options:
+        - Drux 0.4
         - Drux 0.3
         - Drux 0.2
         - Drux 0.1
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a680529..d1f50e8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+## [0.4] - 2026-05-18
 ### Added
 - Hopfenberg model
 ## [0.3] - 2025-12-08
@@ -30,7 +31,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Higuchi model
 
 
-[Unreleased]: https://github.com/openscilab/drux/compare/v0.3...dev
+[Unreleased]: https://github.com/openscilab/drux/compare/v0.4...dev
+[0.4]: https://github.com/openscilab/drux/compare/v0.3...v0.4
 [0.3]: https://github.com/openscilab/drux/compare/v0.2...v0.3
 [0.2]: https://github.com/openscilab/drux/compare/v0.1...v0.2
 [0.1]: https://github.com/openscilab/drux/compare/48548f0...v0.1
\ No newline at end of file
diff --git a/README.md b/README.md
index 61e754b..96f9393 100644
--- a/README.md
+++ b/README.md
@@ -63,9 +63,9 @@ Drux is a Python-based framework for simulating drug release profiles using math
 
 ### PyPI
 - Check [Python Packaging User Guide](https://packaging.python.org/installing/)
-- Run `pip install drux==0.3`
+- Run `pip install drux==0.4`
 ### Source code
-- Download [Version 0.3](https://github.com/openscilab/drux/archive/v0.3.zip) or [Latest Source](https://github.com/openscilab/drux/archive/dev.zip)
+- Download [Version 0.4](https://github.com/openscilab/drux/archive/v0.4.zip) or [Latest Source](https://github.com/openscilab/drux/archive/dev.zip)
 - Run `pip install .`
 
 ## Supported Models
diff --git a/SECURITY.md b/SECURITY.md
index 616e11b..216eb6b 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -4,8 +4,8 @@
 
 | Version       | Supported          |
 | ------------- | ------------------ |
-| 0.3           | :white_check_mark: |
-| < 0.3         | :x:                |
+| 0.4           | :white_check_mark: |
+| < 0.4         | :x:                |
 
 ## Reporting a vulnerability
 
diff --git a/drux/params.py b/drux/params.py
index d17d222..01f2c9b 100644
--- a/drux/params.py
+++ b/drux/params.py
@@ -1,4 +1,4 @@
 # -*- coding: utf-8 -*-
 """Drux parameters and constants."""
 
-DRUX_VERSION = "0.3"
+DRUX_VERSION = "0.4"
diff --git a/otherfiles/meta.yaml b/otherfiles/meta.yaml
index 9fd0019..4376e6e 100644
--- a/otherfiles/meta.yaml
+++ b/otherfiles/meta.yaml
@@ -1,5 +1,5 @@
 {% set name = "drux" %}
-{% set version = "0.3" %}
+{% set version = "0.4" %}
 
 package:
     name: {{ name|lower }}
diff --git a/otherfiles/version_check.py b/otherfiles/version_check.py
index 7724df2..6c7ded4 100644
--- a/otherfiles/version_check.py
+++ b/otherfiles/version_check.py
@@ -4,7 +4,7 @@
 import sys
 import codecs
 Failed = 0
-DRUX_VERSION = "0.3"
+DRUX_VERSION = "0.4"
 
 
 SETUP_ITEMS = [
diff --git a/setup.py b/setup.py
index 9f8c284..ca4431a 100644
--- a/setup.py
+++ b/setup.py
@@ -33,14 +33,14 @@ def read_description() -> str:
     name='drux',
     packages=[
         'drux', ],
-    version='0.3',
+    version='0.4',
     description='Drux: Drug Release Analysis Framework',
     long_description=read_description(),
     long_description_content_type='text/markdown',
     author='Drux Development Team',
     author_email='drux@openscilab.com',
     url='https://github.com/openscilab/drux',
-    download_url='https://github.com/openscilab/drux/tarball/v0.3',
+    download_url='https://github.com/openscilab/drux/tarball/v0.4',
     keywords="drug-release drug-delivery mathematical-modeling simulation kinetics",
     project_urls={
             'Source': 'https://github.com/openscilab/drux',