diff --git a/LICENSE.pdf b/LICENSE.pdf
index d98d3da80..80ae31d51 100644
Binary files a/LICENSE.pdf and b/LICENSE.pdf differ
diff --git a/cicecore/drivers/direct/hadgem3/CICE.F90 b/cicecore/drivers/direct/hadgem3/CICE.F90
index fe322a04d..fac02de9b 100644
--- a/cicecore/drivers/direct/hadgem3/CICE.F90
+++ b/cicecore/drivers/direct/hadgem3/CICE.F90
@@ -1,8 +1,8 @@
 !=======================================================================
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/drivers/mct/cesm1/CICE_copyright.txt b/cicecore/drivers/mct/cesm1/CICE_copyright.txt
index 14d97c481..af2afdf3d 100644
--- a/cicecore/drivers/mct/cesm1/CICE_copyright.txt
+++ b/cicecore/drivers/mct/cesm1/CICE_copyright.txt
@@ -1,7 +1,7 @@
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt b/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
index 14d97c481..af2afdf3d 100644
--- a/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
+++ b/cicecore/drivers/nuopc/cmeps/CICE_copyright.txt
@@ -1,7 +1,7 @@
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/drivers/nuopc/dmi/CICE.F90 b/cicecore/drivers/nuopc/dmi/CICE.F90
index 79dd06fca..5ace27736 100644
--- a/cicecore/drivers/nuopc/dmi/CICE.F90
+++ b/cicecore/drivers/nuopc/dmi/CICE.F90
@@ -1,8 +1,8 @@
 !=======================================================================
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/drivers/standalone/cice/CICE.F90 b/cicecore/drivers/standalone/cice/CICE.F90
index 79dd06fca..5ace27736 100644
--- a/cicecore/drivers/standalone/cice/CICE.F90
+++ b/cicecore/drivers/standalone/cice/CICE.F90
@@ -1,8 +1,8 @@
 !=======================================================================
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/drivers/unittest/opticep/CICE.F90 b/cicecore/drivers/unittest/opticep/CICE.F90
index 79dd06fca..5ace27736 100644
--- a/cicecore/drivers/unittest/opticep/CICE.F90
+++ b/cicecore/drivers/unittest/opticep/CICE.F90
@@ -1,8 +1,8 @@
 !=======================================================================
-! Copyright (c) 2022, Triad National Security, LLC
+! Copyright (c) 2023, Triad National Security, LLC
 ! All rights reserved.
 !
-! Copyright 2022. Triad National Security, LLC. This software was
+! Copyright 2023. Triad National Security, LLC. This software was
 ! produced under U.S. Government contract DE-AC52-06NA25396 for Los
 ! Alamos National Laboratory (LANL), which is operated by Triad
 ! National Security, LLC for the U.S. Department of Energy. The U.S.
diff --git a/cicecore/version.txt b/cicecore/version.txt
index 953395fa1..6f8bbc127 100644
--- a/cicecore/version.txt
+++ b/cicecore/version.txt
@@ -1 +1 @@
-CICE 6.4.1
+CICE 6.4.2
diff --git a/doc/source/conf.py b/doc/source/conf.py
index 7d79f7b43..7d078835c 100644
--- a/doc/source/conf.py
+++ b/doc/source/conf.py
@@ -57,7 +57,7 @@
 
 # General information about the project.
 project = u'CICE'
-copyright = u'2022, Triad National Security, LLC (code) and National Center for Atmospheric Research (documentation)'
+copyright = u'2023, Triad National Security, LLC (code) and National Center for Atmospheric Research (documentation)'
 author = u'CICE-Consortium'
 
 # The version info for the project you're documenting, acts as replacement for
@@ -65,9 +65,9 @@
 # built documents.
 #
 # The short X.Y version.
-version = u'6.4.1' 
+version = u'6.4.2' 
 # The full version, including alpha/beta/rc tags.
-version = u'6.4.1' 
+version = u'6.4.2' 
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/doc/source/intro/copyright.rst b/doc/source/intro/copyright.rst
index 86b15b8d2..e477d9d57 100644
--- a/doc/source/intro/copyright.rst
+++ b/doc/source/intro/copyright.rst
@@ -5,7 +5,7 @@
 Copyright
 =============================
 
-© Copyright 2022, Triad National Security LLC. All rights reserved.
+© Copyright 2023, Triad National Security LLC. All rights reserved.
 This software was produced under U.S. Government contract 
 89233218CNA000001 for Los Alamos National Laboratory (LANL), which is
 operated by Triad National Security, LLC for the U.S. Department
diff --git a/icepack b/icepack
index 23b6c1272..b2bd1a4e6 160000
--- a/icepack
+++ b/icepack
@@ -1 +1 @@
-Subproject commit 23b6c1272b50d42cad7928ffe0005d6ee673dee9
+Subproject commit b2bd1a4e665e7f98f71c46c03903d60db14a59cb