diff --git a/event_model/__init__.py b/event_model/__init__.py
index 038bf59e..78788561 100644
--- a/event_model/__init__.py
+++ b/event_model/__init__.py
@@ -34,6 +34,7 @@
 import numpy
 from typing_extensions import Literal
 
+from .documents import Dtype
 from .documents.datum import Datum
 from .documents.datum_page import DatumPage
 from .documents.event import Event
@@ -61,6 +62,7 @@
 
 
 __all__ = [
+    "Dtype",
     "DocumentNames",
     "schemas",
     "schema_validators",
diff --git a/event_model/documents/__init__.py b/event_model/documents/__init__.py
index f9796a99..e8a2e341 100644
--- a/event_model/documents/__init__.py
+++ b/event_model/documents/__init__.py
@@ -4,7 +4,7 @@
 from event_model.documents.datum import Datum
 from event_model.documents.datum_page import DatumPage
 from event_model.documents.event import Event
-from event_model.documents.event_descriptor import EventDescriptor
+from event_model.documents.event_descriptor import Dtype, EventDescriptor, Limits
 from event_model.documents.event_page import EventPage
 from event_model.documents.resource import Resource
 from event_model.documents.run_start import RunStart
@@ -42,9 +42,11 @@
 __all__ = [
     "Datum",
     "DatumPage",
+    "Dtype",
     "Event",
     "EventDescriptor",
     "EventPage",
+    "Limits",
     "Resource",
     "RunStart",
     "RunStop",
diff --git a/event_model/documents/event_descriptor.py b/event_model/documents/event_descriptor.py
index 2edb99eb..3f570522 100644
--- a/event_model/documents/event_descriptor.py
+++ b/event_model/documents/event_descriptor.py
@@ -7,9 +7,27 @@
 Dtype = Literal["string", "number", "array", "boolean", "integer"]
 
 
+class LimitsRange(TypedDict):
+    low: float
+    high: float
+
+
+class Limits(TypedDict):
+    """
+    Epics limits:
+    see 3.4.1 https://epics.anl.gov/base/R3-14/12-docs/AppDevGuide/node4.html
+    """
+
+    control: NotRequired[Annotated[LimitsRange, Field(description="Control limits.")]]
+    display: NotRequired[Annotated[LimitsRange, Field(description="Display limits.")]]
+    warning: NotRequired[Annotated[LimitsRange, Field(description="Warning limits.")]]
+    alarm: NotRequired[Annotated[LimitsRange, Field(description="Alarm limits.")]]
+
+
 class DataKey(TypedDict):
     """Describes the objects in the data property of Event documents"""
 
+    limits: NotRequired[Annotated[Limits, Field(description="Epics limits.")]]
     dims: NotRequired[
         Annotated[
             List[str],
diff --git a/event_model/schemas/event_descriptor.json b/event_model/schemas/event_descriptor.json
index 0c1bf012..fbf97e15 100644
--- a/event_model/schemas/event_descriptor.json
+++ b/event_model/schemas/event_descriptor.json
@@ -58,6 +58,10 @@
                     "type": "string",
                     "pattern": "^[A-Z]+:?"
                 },
+                "limits": {
+                    "description": "Epics limits.",
+                    "$ref": "#/$defs/Limits"
+                },
                 "object_name": {
                     "title": "Object Name",
                     "description": "The name of the object this key was pulled from.",
@@ -93,6 +97,47 @@
                 "source"
             ]
         },
+        "Limits": {
+            "title": "Limits",
+            "description": "Epics limits:\nsee 3.4.1 https://epics.anl.gov/base/R3-14/12-docs/AppDevGuide/node4.html",
+            "type": "object",
+            "properties": {
+                "alarm": {
+                    "description": "Alarm limits.",
+                    "$ref": "#/$defs/LimitsRange"
+                },
+                "control": {
+                    "description": "Control limits.",
+                    "$ref": "#/$defs/LimitsRange"
+                },
+                "display": {
+                    "description": "Display limits.",
+                    "$ref": "#/$defs/LimitsRange"
+                },
+                "warning": {
+                    "description": "Warning limits.",
+                    "$ref": "#/$defs/LimitsRange"
+                }
+            }
+        },
+        "LimitsRange": {
+            "title": "LimitsRange",
+            "type": "object",
+            "properties": {
+                "high": {
+                    "title": "High",
+                    "type": "number"
+                },
+                "low": {
+                    "title": "Low",
+                    "type": "number"
+                }
+            },
+            "required": [
+                "high",
+                "low"
+            ]
+        },
         "PerObjectHint": {
             "title": "PerObjectHint",
             "description": "The 'interesting' data keys for this device.",