diff --git a/LICENSE.rst b/LICENSE.rst
new file mode 100644
index 00000000..475ec731
--- /dev/null
+++ b/LICENSE.rst
@@ -0,0 +1,29 @@
+BSD 3-Clause License
+
+Copyright (c) 2017, Smithsonian Astrophysical Observatory
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the copyright holder nor the names of its
+  contributors may be used to endorse or promote products derived from
+  this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/alt_core/core_python.py b/alt_core/core_python.py
index d5a2f6c3..48cbe7c6 100644
--- a/alt_core/core_python.py
+++ b/alt_core/core_python.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import numpy as np
 
 def calc_model(indexes, dt, n_preds, mvals, parvals, mults, heats, heatsinks):
diff --git a/doc/conf.py b/doc/conf.py
index 55c9a2c8..9f068451 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -11,6 +11,7 @@
 #
 # All configuration values have a default; values that are commented out
 # serve to show the default.
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 
 import sys
 import os
diff --git a/examples/doc/example1.py b/examples/doc/example1.py
index 32e7e3b4..7fbda92d 100644
--- a/examples/doc/example1.py
+++ b/examples/doc/example1.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Example with a single node (ACA CCD temperature) with solar heating
 (2 bins).
diff --git a/examples/doc/example2.py b/examples/doc/example2.py
index 8b217c53..79ed0fc8 100644
--- a/examples/doc/example2.py
+++ b/examples/doc/example2.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Example with a single node (ACA CCD temperature) with solar heating
 (2 bins) and a heat sink.
diff --git a/examples/doc/example3.py b/examples/doc/example3.py
index 3d92ed82..f89bb54f 100644
--- a/examples/doc/example3.py
+++ b/examples/doc/example3.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Example with a single node (ACA CCD temperature) with solar heating
 (2 bins) and a heat sink.
diff --git a/examples/doc/example3_fit.py b/examples/doc/example3_fit.py
index 70c72ca5..0998cc58 100644
--- a/examples/doc/example3_fit.py
+++ b/examples/doc/example3_fit.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import sys
 import xija
 
diff --git a/examples/doc/example4.py b/examples/doc/example4.py
index f6948a5f..9ea0623b 100644
--- a/examples/doc/example4.py
+++ b/examples/doc/example4.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import sys
 import xija
 
diff --git a/examples/dpa/plot_dpa_resid.py b/examples/dpa/plot_dpa_resid.py
index 3a2f56a6..70aba8a2 100644
--- a/examples/dpa/plot_dpa_resid.py
+++ b/examples/dpa/plot_dpa_resid.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import xija
 import numpy as np
 import matplotlib.pyplot as plt
diff --git a/fit.py b/fit.py
index a7680174..c26f774b 100755
--- a/fit.py
+++ b/fit.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 
 import os
 import sys
diff --git a/gui_fit.py b/gui_fit.py
index 91481817..be0928ad 100755
--- a/gui_fit.py
+++ b/gui_fit.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Run the gui_fit tool
 """
diff --git a/models/acisfp/calc_model.py b/models/acisfp/calc_model.py
index cb0b3a1d..d9ac685f 100644
--- a/models/acisfp/calc_model.py
+++ b/models/acisfp/calc_model.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """Sample code for calculating the ACIS FP Xija model.
 
 This shows necessary inputs and runs without using the eng archive.
diff --git a/models/minusz/make_minusz.py b/models/minusz/make_minusz.py
index 358ce9dc..cb23a670 100644
--- a/models/minusz/make_minusz.py
+++ b/models/minusz/make_minusz.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Replicate (mostly) the minusz TEPHIN node model.  (dPs set to zero though).
 
diff --git a/models/psmc/make_psmc_from_twodof.py b/models/psmc/make_psmc_from_twodof.py
index 6a56bdd3..4632dd0b 100644
--- a/models/psmc/make_psmc_from_twodof.py
+++ b/models/psmc/make_psmc_from_twodof.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import xija
 import numpy as np
 import asciitable
diff --git a/setup.py b/setup.py
index f5291e9a..cf76614d 100644
--- a/setup.py
+++ b/setup.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from setuptools import setup, Extension
 import os
 from xija import __version__
diff --git a/tests_no_pytest/test_minimal_onedof.py b/tests_no_pytest/test_minimal_onedof.py
index a139e176..84ea4834 100644
--- a/tests_no_pytest/test_minimal_onedof.py
+++ b/tests_no_pytest/test_minimal_onedof.py
@@ -1,5 +1,6 @@
 # Build the core.so module and put into the source directory.
 # python setup.py build_ext --inplace
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 
 import xija
 
diff --git a/tests_no_pytest/test_minimal_twodof.py b/tests_no_pytest/test_minimal_twodof.py
index fccdb312..118b3bfb 100644
--- a/tests_no_pytest/test_minimal_twodof.py
+++ b/tests_no_pytest/test_minimal_twodof.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import numpy as np
 import xija
 
diff --git a/tests_no_pytest/test_minusz.py b/tests_no_pytest/test_minusz.py
index 5233c207..844bd4dc 100644
--- a/tests_no_pytest/test_minusz.py
+++ b/tests_no_pytest/test_minusz.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Replicate (mostly) the minusz TEPHIN node model.  (dPs set to zero though).
 """
diff --git a/tests_no_pytest/test_minusz_proto.py b/tests_no_pytest/test_minusz_proto.py
index e1b9dbb3..6caa34d1 100644
--- a/tests_no_pytest/test_minusz_proto.py
+++ b/tests_no_pytest/test_minusz_proto.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Replicate (mostly) the minusz TEPHIN node model.  (dPs set to zero though).
 """
diff --git a/tests_no_pytest/test_write.py b/tests_no_pytest/test_write.py
index 1ffafa69..f72ba3d5 100644
--- a/tests_no_pytest/test_write.py
+++ b/tests_no_pytest/test_write.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import os
 import json
 import numpy as np
diff --git a/worker.py b/worker.py
index f44d14f1..8b6ffb9e 100644
--- a/worker.py
+++ b/worker.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Worker
 """
diff --git a/xija/__init__.py b/xija/__init__.py
index 7bad318d..69c7f48a 100644
--- a/xija/__init__.py
+++ b/xija/__init__.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from .model import *
 from .component import *
 from .files import files
diff --git a/xija/clogging.py b/xija/clogging.py
index a11454bf..b7a57ace 100644
--- a/xija/clogging.py
+++ b/xija/clogging.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import logging
 from logging import DEBUG, INFO, WARNING, CRITICAL, ERROR
 import sys
diff --git a/xija/component/__init__.py b/xija/component/__init__.py
index 18c2ade6..dc836406 100644
--- a/xija/component/__init__.py
+++ b/xija/component/__init__.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from .base import *
 from .mask import *
 from .heat import *
diff --git a/xija/component/base.py b/xija/component/base.py
index 1f64601b..65bf9144 100644
--- a/xija/component/base.py
+++ b/xija/component/base.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import numpy as np
 import six
 
diff --git a/xija/component/experimental.py b/xija/component/experimental.py
index 89977759..60a9badb 100644
--- a/xija/component/experimental.py
+++ b/xija/component/experimental.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import numpy as np
 
 try:
diff --git a/xija/component/heat.py b/xija/component/heat.py
index abf4149d..384da362 100644
--- a/xija/component/heat.py
+++ b/xija/component/heat.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from __future__ import print_function
 
 import re
diff --git a/xija/component/mask.py b/xija/component/mask.py
index 1fd7183f..3bc6a171 100644
--- a/xija/component/mask.py
+++ b/xija/component/mask.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 import operator
 
 import numpy as np
diff --git a/xija/convert.py b/xija/convert.py
index 1c179a89..cc1d8016 100644
--- a/xija/convert.py
+++ b/xija/convert.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from __future__ import print_function
 
 import sys
diff --git a/xija/files.py b/xija/files.py
index 6235a28e..23d19724 100644
--- a/xija/files.py
+++ b/xija/files.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 files = dict(model_spec =   '{{src.model}}/{{src.model}}',
              out_dir  =     '{{src.model}}/{{src.outdir}}',
              out_values =   '{{src.model}}/{{src.outdir}}/values',
diff --git a/xija/gui_fit.py b/xija/gui_fit.py
index bf51b20c..cb9b3bc0 100755
--- a/xija/gui_fit.py
+++ b/xija/gui_fit.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 
 from __future__ import print_function
 
diff --git a/xija/model.py b/xija/model.py
index b23ed307..d4d02156 100644
--- a/xija/model.py
+++ b/xija/model.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 """
 Xija - framework to model complex time-series data using a network of
 coupled nodes with pluggable model components that define the node
diff --git a/xija/tests/test_models.py b/xija/tests/test_models.py
index 1884ff19..b7176978 100644
--- a/xija/tests/test_models.py
+++ b/xija/tests/test_models.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 from __future__ import print_function
 
 import os
diff --git a/xija/tmal.py b/xija/tmal.py
index fa181667..0a58bb34 100644
--- a/xija/tmal.py
+++ b/xija/tmal.py
@@ -1,3 +1,4 @@
+# Licensed under a 3-clause BSD style license - see LICENSE.rst
 OPCODES = {'coupling': 0,
            'heatsink': 1,
            'precomputed_heat': 2,