diff --git a/x-pack/plugins/ingest_manager/common/openapi/spec_oas3.json b/x-pack/plugins/ingest_manager/common/openapi/spec_oas3.json
index a780ae5599793..329137b063e66 100644
--- a/x-pack/plugins/ingest_manager/common/openapi/spec_oas3.json
+++ b/x-pack/plugins/ingest_manager/common/openapi/spec_oas3.json
@@ -3520,6 +3520,172 @@
         }
       }
     },
+    "/fleet/agents/{agentId}/upgrade": {
+      "parameters": [
+        {
+          "schema": {
+            "type": "string"
+          },
+          "name": "agentId",
+          "in": "path",
+          "required": true
+        }
+      ],
+      "post": {
+        "summary": "Fleet - Agent - Upgrade",
+        "tags": [],
+                "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/UpgradeAgent"
+                },
+                "examples": {
+                  "success": {
+                    "value": {}
+                  }
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "BAD REQUEST",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/UpgradeAgent"
+                },
+                "examples": {
+                  "bad request not upgradeable": {
+                    "value": {
+                      "statusCode": 400,
+                      "error": "Bad Request",
+                       "message": "agent d133b07d-5c2b-42f0-8e6b-bbae53bdce88 is not upgradeable"
+                    }
+                  },
+                  "bad request kibana version": {
+                    "value": {
+                      "statusCode": 400,
+                      "error": "Bad Request",
+                       "message": "cannot upgrade agent to 8.0.0 because it is different than the installed kibana version 7.9.10"
+                    }
+                  },
+                  "bad request agent unenrolling": {
+                    "value": {
+                      "statusCode": 400,
+                      "error": "Bad Request",
+                       "message": "cannot upgrade an unenrolling or unenrolled agent"
+                    }
+                  }
+                }
+              }
+            }
+          }
+        },
+        "operationId": "post-fleet-agents-upgrade",
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/xsrfHeader"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/UpgradeAgent"
+              },
+              "examples":{
+                "version":{
+                   "value": {
+                     "version": "8.0.0"
+                   }
+                },
+                "version and source_uri":{
+                   "value": {
+                     "version": "8.0.0",
+                     "source_uri": "http://localhost:8000"
+                   }
+                }
+              }
+            }
+          }
+        }
+      }
+    },
+    "/fleet/agents/bulk_upgrade": {
+      "post": {
+        "summary": "Fleet - Agent - Bulk Upgrade",
+        "tags": [],
+                "responses": {
+          "200": {
+            "description": "OK",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/BulkUpgradeAgents"
+                },
+                "examples": {
+                  "success": {
+                    "value": {}
+                  }
+                }
+              }
+            }
+          },
+          "400": {
+            "description": "BAD REQUEST",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/UpgradeAgent"
+                },
+                "examples": {
+                  "bad request kibana version": {
+                    "value": {
+                      "statusCode": 400,
+                      "error": "Bad Request",
+                       "message": "cannot upgrade agent to 8.0.0 because it is different than the installed kibana version 7.9.10"
+                    }
+                  }
+                }
+              }
+            }
+          }
+        },
+        "operationId": "post-fleet-agents-bulk-upgrade",
+        "parameters": [
+          {
+            "$ref": "#/components/parameters/xsrfHeader"
+          }
+        ],
+        "requestBody": {
+          "required": true,
+          "content": {
+            "application/json": {
+              "schema": {
+                "$ref": "#/components/schemas/BulkUpgradeAgents"
+              },
+              "examples":{
+                "version":{
+                   "value": {
+                     "version": "8.0.0"
+                   }
+                },
+                "version and source_uri":{
+                   "value": {
+                     "version": "8.0.0",
+                     "source_uri": "http://localhost:8000"
+                   }
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/fleet/agent-status": {
       "get": {
         "summary": "Fleet - Agent - Status for policy",
@@ -4226,8 +4392,88 @@
         "type": "string",
         "title": "EnrollmentApiKey",
         "format": "byte"
+      },
+      "UpgradeAgent":{
+        "title": "UpgradeAgent",
+        "oneOf": [
+          { 
+            "type": "object",
+            "properties": {
+              "version": {
+                "type": "string"
+              }
+            },
+            "required": ["version"]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "version": {
+                "type": "string"
+              },
+              "source_uri": {
+                "type": "string"
+              }
+            },
+            "required": ["version"]
+          }
+        ]
+      },
+    "BulkUpgradeAgents":{
+        "title": "BulkUpgradeAgents",
+        "oneOf": [
+          { 
+            "type": "object",
+            "properties": {
+              "version": {
+                "type": "string"
+              },
+              "agents":{
+                "type": "array",
+                "items":{
+                  "type": "string"
+                }
+              }
+            },
+            "required": ["version", "agents"]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "version": {
+                "type": "string"
+              },
+              "source_uri": {
+                "type": "string"
+              },
+             "agents":{
+                "type": "array",
+                "items":{
+                  "type": "string"
+                }
+              }
+            },
+            "required": ["version", "agents"]
+          },
+          {
+            "type": "object",
+            "properties": {
+              "version": {
+                "type": "string"
+              },
+              "source_uri": {
+                "type": "string"
+              },
+             "agents":{
+                "type": "string"
+              }
+            },
+            "required": ["version", "agents"]
+          }
+        ]
       }
     },
+    
     "parameters": {
       "pageSizeParam": {
         "name": "perPage",
diff --git a/x-pack/plugins/ingest_manager/server/routes/agent/upgrade_handler.ts b/x-pack/plugins/ingest_manager/server/routes/agent/upgrade_handler.ts
index c4aa33999cf22..9c6b50b6d8f09 100644
--- a/x-pack/plugins/ingest_manager/server/routes/agent/upgrade_handler.ts
+++ b/x-pack/plugins/ingest_manager/server/routes/agent/upgrade_handler.ts
@@ -16,6 +16,8 @@ import * as AgentService from '../../services/agents';
 import { appContextService } from '../../services';
 import { defaultIngestErrorHandler } from '../../errors';
 import { AGENT_SAVED_OBJECT_TYPE } from '../../constants';
+import { savedObjectToAgent } from '../../services/agents/saved_objects';
+import { isAgentUpgradeable } from '../../../common/services';
 
 export const postAgentUpgradeHandler: RequestHandler<
   TypeOf<typeof PostAgentUpgradeRequestSchema.params>,
@@ -35,15 +37,25 @@ export const postAgentUpgradeHandler: RequestHandler<
       },
     });
   }
-  const agent = await soClient.get<AgentSOAttributes>(
+  const agentSO = await soClient.get<AgentSOAttributes>(
     AGENT_SAVED_OBJECT_TYPE,
     request.params.agentId
   );
-  if (agent.attributes.unenrollment_started_at || agent.attributes.unenrolled_at) {
+  if (agentSO.attributes.unenrollment_started_at || agentSO.attributes.unenrolled_at) {
     return response.customError({
       statusCode: 400,
       body: {
-        message: `cannot upgrade an unenrolling or unenrolled agent`,
+        message: 'cannot upgrade an unenrolling or unenrolled agent',
+      },
+    });
+  }
+
+  const agent = savedObjectToAgent(agentSO);
+  if (!isAgentUpgradeable(agent, kibanaVersion)) {
+    return response.customError({
+      statusCode: 400,
+      body: {
+        message: `agent ${request.params.agentId} is not upgradeable`,
       },
     });
   }
diff --git a/x-pack/test/ingest_manager_api_integration/apis/fleet/agents/upgrade.ts b/x-pack/test/ingest_manager_api_integration/apis/fleet/agents/upgrade.ts
index 04e32b2b80f56..ed0d6ff97e986 100644
--- a/x-pack/test/ingest_manager_api_integration/apis/fleet/agents/upgrade.ts
+++ b/x-pack/test/ingest_manager_api_integration/apis/fleet/agents/upgrade.ts
@@ -29,6 +29,13 @@ export default function (providerContext: FtrProviderContext) {
 
     it('should respond 200 to upgrade agent and update the agent SO', async () => {
       const kibanaVersion = await kibanaServer.version.get();
+      await kibanaServer.savedObjects.update({
+        id: 'agent1',
+        type: AGENT_SAVED_OBJECT_TYPE,
+        attributes: {
+          local_metadata: { elastic: { agent: { upgradeable: true, version: '0.0.0' } } },
+        },
+      });
       await supertest
         .post(`/api/ingest_manager/fleet/agents/agent1/upgrade`)
         .set('kbn-xsrf', 'xxx')
@@ -45,6 +52,13 @@ export default function (providerContext: FtrProviderContext) {
     });
     it('should respond 200 to upgrade agent and update the agent SO without source_uri', async () => {
       const kibanaVersion = await kibanaServer.version.get();
+      await kibanaServer.savedObjects.update({
+        id: 'agent1',
+        type: AGENT_SAVED_OBJECT_TYPE,
+        attributes: {
+          local_metadata: { elastic: { agent: { upgradeable: true, version: '0.0.0' } } },
+        },
+      });
       await supertest
         .post(`/api/ingest_manager/fleet/agents/agent1/upgrade`)
         .set('kbn-xsrf', 'xxx')
@@ -102,8 +116,21 @@ export default function (providerContext: FtrProviderContext) {
         .expect(400);
     });
 
+    it('should respond 400 if trying to upgrade an agent that is not upgradeable', async () => {
+      const kibanaVersion = await kibanaServer.version.get();
+      const res = await supertest
+        .post(`/api/ingest_manager/fleet/agents/agent1/upgrade`)
+        .set('kbn-xsrf', 'xxx')
+        .send({
+          version: kibanaVersion,
+        })
+        .expect(400);
+      expect(res.body.message).to.equal('agent agent1 is not upgradeable');
+    });
+
     it('should respond 200 to bulk upgrade agents and update the agent SOs', async () => {
       const kibanaVersion = await kibanaServer.version.get();
+
       await supertest
         .post(`/api/ingest_manager/fleet/agents/bulk_upgrade`)
         .set('kbn-xsrf', 'xxx')