diff --git a/autotest/test_codec.py b/autotest/test_codec.py
new file mode 100644
index 00000000..1a04959a
--- /dev/null
+++ b/autotest/test_codec.py
@@ -0,0 +1,19 @@
+from pprint import pprint
+
+import pytest
+
+import modflow_devtools.models as models
+from modflow_devtools.codec import make_parser
+
+MODELS = [name for name in models.get_models().keys() if name.startswith("mf6/")]
+PARSER = make_parser()
+
+
+@pytest.mark.parametrize("model_name", MODELS)
+def test_parser(model_name, function_tmpdir):
+    workspace = models.copy_to(function_tmpdir, model_name)
+    nam_path = next(iter(workspace.glob("*.nam")))
+    text = nam_path.open().read()
+    pprint(text)
+    tree = PARSER.parse(text)
+    print(tree.pretty())
diff --git a/docs/md/codec.md b/docs/md/codec.md
new file mode 100644
index 00000000..e69de29b
diff --git a/modflow_devtools/codec.py b/modflow_devtools/codec.py
new file mode 100644
index 00000000..9506fcb3
--- /dev/null
+++ b/modflow_devtools/codec.py
@@ -0,0 +1,5 @@
+from lark import Lark
+
+
+def make_parser(**kwargs) -> Lark:
+    return Lark.open("mf6.lark", parser="lalr", rel_to=__file__, **kwargs)
diff --git a/modflow_devtools/mf6.lark b/modflow_devtools/mf6.lark
new file mode 100644
index 00000000..cd64e2bb
--- /dev/null
+++ b/modflow_devtools/mf6.lark
@@ -0,0 +1,19 @@
+start: [WS] [_NL*] (block [[WS] _NL*])+ [WS]
+block: "begin"i CNAME [_block_index] _NL _content "end"i CNAME [_block_index] _NL+
+_block_index: INT
+_content: line* [WS]
+line: [WS] item* _NL+
+item: word | NUMBER
+word: /[a-zA-Z0-9._'~,-\\(\\)]+/
+
+%import common.NEWLINE -> _NL
+%import common.WS
+%import common.WS_INLINE
+%import common.CNAME
+%import common.WORD
+%import common.NUMBER
+%import common.INT
+%import common.SH_COMMENT
+%import common._STRING_INNER
+%ignore WS_INLINE
+%ignore SH_COMMENT
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index e8f637ae..b0c81a9f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -81,6 +81,9 @@ models = [
     "tomli",
     "tomli-w"
 ]
+codec = [
+    "lark"
+]
 dev = ["modflow-devtools[lint,test,docs,dfn,models]"]
 
 [dependency-groups]
@@ -126,6 +129,9 @@ models = [
     "tomli",
     "tomli-w"
 ]
+codec = [
+    "lark"
+]
 dev = [
     {include-group = "build"},
     {include-group = "lint"},
@@ -133,6 +139,7 @@ dev = [
     {include-group = "docs"},
     {include-group = "dfn"},
     {include-group = "models"},
+    {include-group = "codec"},
 ]
 
 [project.urls]