diff --git a/diag_manager/README.md b/diag_manager/README.md
index 60ab87bbd..ddf0dac68 100644
--- a/diag_manager/README.md
+++ b/diag_manager/README.md
@@ -1,4 +1,4 @@
-The purpose of this document is to document the differences between the old diag manager and the new (modern) diag manager. 
+The purpose of this document is to document the differences between the old diag manager and the new (modern) diag manager.
 
 ## Contents
 - [1. Diag Table Format](README.md#1-diag-table-format)
@@ -10,7 +10,9 @@ The purpose of this document is to document the differences between the old diag
 - [7. History files data output "changes"](README.md#7-history-files-data-output-changes)
 
 ### 1. Diag Table Format
-The modern diag manager uses a YAML format instead of the legacy ascii table. A description of the YAML diag table can be found [here](diag_yaml_format.md).
+The modern diag manager uses a YAML format instead of the legacy ascii table. A description of the YAML diag table can
+be found [here](diag_yaml_format.md). A formal specification, in the form of a JSON schema, can be found in the
+[gfdl_msd_schemas](https://github.com/NOAA-GFDL/gfdl_msd_schemas) repository on Github.
 
 ### 2. Scalar Axis
 The old diag manager was adding a `scalar_axis` dimension of size 1 for scalar variables
@@ -70,7 +72,7 @@ This time_bounds variable is refernced as a variable attribute of time:
 ### 4. Subregional Files
 
 #### A. `is_subregional` global attribute:
-Subregional files will have a global NetCDF attribute `is_subregional = True` set for non-global history files. This attribute will be used in PP tools. 
+Subregional files will have a global NetCDF attribute `is_subregional = True` set for non-global history files. This attribute will be used in PP tools.
 
 #### B. Subregional dimension names:
 In some cases, the old diag manager was adding `sub0X` to the dimension names where X is a number greater than 1. This was causing problems in PP tools that were expecting the dimension to have `sub01` in the name. The new diag manager will not have this problem.
diff --git a/diag_manager/diag_yaml_format.md b/diag_manager/diag_yaml_format.md
index 63ed4630c..d8221956d 100644
--- a/diag_manager/diag_yaml_format.md
+++ b/diag_manager/diag_yaml_format.md
@@ -14,6 +14,7 @@ The purpose of this document is to explain the diag_table yaml format.
 - [2.5 Global Meta Data Section](diag_yaml_format.md#25-global-meta-data-section)
 - [2.6 Sub_region Section](diag_yaml_format.md#26-sub_region-section)
 - [3. More examples](diag_yaml_format.md#3-more-examples)
+- [4. Schema](diag_yaml_format.md#4-schema)
 
 ### 1. Converting from legacy ascii diag_table format
 
@@ -340,3 +341,8 @@ diag_files:
   unlimdim: records
   write_file: false
 ```
+
+### 4. Schema
+A formal specification of the file format, in the form of a JSON schema, can be
+found in the [gfdl_msd_schemas](https://github.com/NOAA-GFDL/gfdl_msd_schemas)
+repository on Github.
diff --git a/diag_manager/schema.diag b/diag_manager/schema.diag
deleted file mode 100644
index b232577ff..000000000
--- a/diag_manager/schema.diag
+++ /dev/null
@@ -1,141 +0,0 @@
-{
-  "$schema": "http://json-schema.org/draft-04/schema#",
-  "type": "object",
-  "required": ["title", "base_date"],
-  "additionalProperties": false,
-  "properties": {
-    "title": {
-      "type": "string"
-    },
-    "base_date": {
-      "type": "string"
-    },
-    "diag_files": {
-      "type": "array",
-      "items": {
-        "type": "object",
-        "required": ["file_name", "freq", "time_units", "unlimdim"],
-        "additionalProperties": false,
-        "properties": {
-          "file_name": {
-            "type": "string"
-          },
-          "freq": {
-            "anyOf": [
-              {"type": "string"},
-              {"type": "number"}
-            ],
-            "pattern": "^-[1]{1,1} *[ seconds| minutes| hours| days| months| years]*|^0&|^[1-9]+ [seconds|minutes|hours|days|months|years]{1,1}"
-          },
-          "time_units": {
-            "type": "string",
-            "enum": ["seconds", "minutes", "hours", "days", "months", "years"]
-          },
-          "unlimdim": {
-            "type": "string"
-          },
-          "write_file": {
-            "type": "boolean"
-          },
-          "global_meta": {
-          },
-          "sub_region": {
-            "type": "array",
-            "minItems": 1,
-            "maxItems": 1,
-            "required": ["grid_type", "corner1", "corner2", "corner3", "corner4"],
-            "properties": {
-              "grid_type": {
-                "type": "string",
-                "enum": ["indices", "latlon"]
-              },
-              "corner1": {
-                "type": "array",
-                "minItems": 2,
-                "maxItems": 2,
-                "items": {
-                  "type": "number"
-                }
-              },
-              "corner2": {
-                "type": "array",
-                "minItems": 2,
-                "maxItems": 2,
-                "items": {
-                  "type": "number"
-                }
-              },
-              "corner3": {
-                "type": "array",
-                "minItems": 2,
-                "maxItems": 2,
-                "items": {
-                  "type": "number"
-                }
-              },
-              "corner4": {
-                "type": "array",
-                "minItems": 2,
-                "maxItems": 2,
-                "items": {
-                  "type": "number"
-                }
-              },
-              "tile": {
-                "type": "number"
-              }
-            }
-          },
-          "new_file_freq": {
-            "type": "string",
-            "pattern": "[0-9]{1,} [a-z]{1,}"
-          },
-          "start_time": {
-            "type": "string"
-          },
-          "file_duration": {
-            "type": "string"
-          },
-          "varlist": {
-            "type": "array",
-            "items": {
-              "type": "object",
-              "required": ["var_name", "reduction", "module", "kind"],
-              "additionalProperties": false,
-              "properties": {
-                "kind": {
-                  "type": "string",
-                  "enum": ["r4", "r8", "i4", "i8"]
-                },
-                "module": {
-                  "type": "string"
-                },
-                "reduction": {
-                  "type": "string",
-                  "pattern": "^average$|^min$|^max$|^none$|^rms$|^sum$|^diurnal[1-9]+|^pow[1-9]+"
-                },
-                "var_name": {
-                  "type": "string"
-                },
-                "write_var": {
-                  "type": "boolean"
-                },
-                "output_name": {
-                  "type": "string"
-                },
-                "long_name": {
-                  "type": "string"
-                },
-                "attributes": {
-                },
-               "zbounds": {
-                  "type": "string"
-                }
-              }
-            }
-          }
-        }
-      }
-    }
-  }
-}