diff --git a/package.json b/package.json
index 9b5581c..9eaa1ca 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@eyeseetea/d2-api",
     "description": "Typed wrapper over DHIS2 API",
-    "version": "1.9.2",
+    "version": "1.9.3",
     "license": "GPL-3.0",
     "author": "EyeSeeTea team",
     "repository": {
diff --git a/src/api/d2Api.ts b/src/api/d2Api.ts
index 3e094d4..2996305 100644
--- a/src/api/d2Api.ts
+++ b/src/api/d2Api.ts
@@ -20,9 +20,10 @@ import { MessageConversations } from "./messageConversations";
 import { Metadata } from "./metadata";
 import { Model } from "./model";
 import { Sharing } from "./sharing";
+import { SqlViews } from "./SqlViews";
 import { System } from "./system";
+import { TrackedEntityInstances } from "./trackedEntityInstances";
 import { D2ApiOptions, D2ApiRequest, IndexedModels } from "./types";
-import { SqlViews } from "./SqlViews";
 
 export class D2ApiGeneric {
     public baseUrl: string;
@@ -141,6 +142,11 @@ export abstract class D2ApiVersioned<
         return new Events(this);
     }
 
+    @cache()
+    get trackedEntityInstances() {
+        return new TrackedEntityInstances(this);
+    }
+
     @cache()
     get system() {
         return new System(this);
diff --git a/src/api/system.ts b/src/api/system.ts
index ef57ae9..fe41652 100644
--- a/src/api/system.ts
+++ b/src/api/system.ts
@@ -6,6 +6,7 @@ import { D2ApiGeneric } from "./d2Api";
 import { DataValueSetsPostResponse } from "./dataValues";
 import { EventsPostResponse } from "./events";
 import { MetadataResponse } from "./metadata";
+import { TeiPostResponse } from "./trackedEntityInstances";
 
 export class System {
     constructor(public d2Api: D2ApiGeneric) {}
@@ -209,4 +210,5 @@ export type WaitForResponse = {
     DATAVALUE_IMPORT: DataValueSetsPostResponse;
     EVENT_IMPORT: EventsPostResponse;
     METADATA_IMPORT: MetadataResponse;
+    TEI_IMPORT: TeiPostResponse;
 };
diff --git a/src/api/trackedEntityInstances.ts b/src/api/trackedEntityInstances.ts
new file mode 100644
index 0000000..9d5c36a
--- /dev/null
+++ b/src/api/trackedEntityInstances.ts
@@ -0,0 +1,197 @@
+import { Id, Pager } from "./base";
+import { AsyncPostResponse, D2ApiResponse, HttpResponse } from "./common";
+import { D2ApiGeneric } from "./d2Api";
+
+export class TrackedEntityInstances {
+    constructor(public d2Api: D2ApiGeneric) {}
+
+    get(params: TeiGetRequest): D2ApiResponse<PaginatedTeiGetResponse> {
+        return this.d2Api.get<PaginatedTeiGetResponse>("/trackedEntityInstances", {
+            ...params,
+            ou: params.ou ? params.ou.join(";") : undefined,
+            paging: true,
+        });
+    }
+
+    getAll(params: TeiGetRequest): D2ApiResponse<TeiGetResponse> {
+        return this.d2Api.get<TeiGetResponse>("/trackedEntityInstances", {
+            ...params,
+            ou: params.ou ? params.ou.join(";") : undefined,
+            paging: false,
+            page: undefined,
+            pageSize: undefined,
+        });
+    }
+
+    post(
+        params: TeiPostParams,
+        request: TeiPostRequest
+    ): D2ApiResponse<HttpResponse<TeiPostResponse>> {
+        return this.d2Api.post<HttpResponse<TeiPostResponse>>(
+            "/trackedEntityInstances",
+            { ...params, async: false },
+            request
+        );
+    }
+
+    postAsync(
+        params: TeiPostParams,
+        request: TeiPostRequest
+    ): D2ApiResponse<AsyncPostResponse<"TEI_IMPORT">> {
+        return this.d2Api.post<AsyncPostResponse<"TEI_IMPORT">>(
+            "/trackedEntityInstances",
+            { ...params, async: true },
+            request
+        );
+    }
+}
+
+export interface TrackedEntityInstance {
+    trackedEntityInstance: Id;
+    trackedEntityType: Id;
+    inactive: boolean;
+    orgUnit: Id;
+    attributes: Attribute[];
+    enrollments: Enrollment[];
+    relationships: Relationship[];
+}
+
+export interface Relationship {
+    relationship: Id;
+    relationshipType: Id;
+    relationshipName: string;
+    from: RelationshipItem;
+    to: RelationshipItem;
+}
+
+export interface RelationshipItem {
+    trackedEntityInstance?: {
+        trackedEntityInstance: Id;
+    };
+    event?: { event: Id };
+}
+
+export interface Enrollment {
+    enrollment: Id;
+    program: Id;
+    orgUnit: Id;
+    enrollmentDate: string;
+    incidentDate: string;
+    events?: Event[];
+}
+
+export interface AttributeValue {
+    attribute: Attribute;
+    value: string;
+    optionId?: Id;
+}
+
+export interface Attribute {
+    attribute: Id;
+    valueType?: string;
+    value: string;
+}
+
+export type TeiOuRequest =
+    | { ouMode?: "ACCESSIBLE" | "CAPTURE" | "ALL"; ou?: never[] }
+    | { ouMode?: "SELECTED" | "CHILDREN" | "DESCENDANTS"; ou: Id[] };
+
+export type TeiGetRequest = TeiOuRequest & {
+    // Program and tracked entity type cannot be specified simultaneously
+    program?: Id;
+    trackedEntityType?: Id;
+    programStatus?: "ACTIVE" | "COMPLETED" | "CANCELLED";
+    followUp?: boolean;
+    order?: string;
+    pageSize?: number;
+    page?: number;
+    totalPages: true;
+    fields?: string; // TODO: Add inference
+    programStartDate?: string;
+    programEndDate?: string;
+    lastUpdatedStartDate?: string;
+    lastUpdatedEndDate?: string;
+    lastUpdatedDuration?: string;
+    assignedUserMode?: "CURRENT" | "PROVIDED" | "NONE" | "ANY";
+    trackedEntityInstance?: string;
+    includeDeleted?: boolean;
+};
+
+export interface TeiGetResponse {
+    trackedEntityInstances: TrackedEntityInstance[];
+}
+
+export interface PaginatedTeiGetResponse extends TeiGetResponse {
+    pager: Pager;
+}
+
+export interface TeiPostRequest {
+    trackedEntityInstances: Array<{
+        trackedEntityInstance: Id;
+        trackedEntityType: Id;
+        inactive?: boolean;
+        orgUnit: Id;
+        attributes: Attribute[];
+        enrollments: Enrollment[];
+        relationships: Relationship[];
+    }>;
+}
+
+export type TeiPostParams = Partial<{
+    idScheme: string;
+    dataElementIdScheme: string;
+    orgUnitIdScheme: string;
+    skipNotifications: boolean;
+    skipFirst: boolean;
+    strategy: "CREATE" | "UPDATE" | "CREATE_AND_UPDATE" | "DELETE";
+    importReportMode: "FULL" | "ERRORS" | "DEBUG";
+    async: boolean;
+    dryRun: boolean;
+}>;
+
+export interface TeiPostResponse {
+    responseType: "ImportSummaries";
+    status: "ERROR" | "SUCCESS";
+    imported: number;
+    updated: number;
+    deleted: number;
+    ignored: number;
+    total: number;
+    importSummaries?: Array<
+        | {
+              responseType: "ImportSummary";
+              status: "ERROR";
+              reference?: string;
+              conflicts: Array<{
+                  object: string;
+                  value: string;
+              }>;
+              importCount: {
+                  imported: number;
+                  updated: number;
+                  ignored: number;
+                  deleted: number;
+              };
+          }
+        | {
+              responseType: "ImportSummary";
+              status: "SUCCESS";
+              reference: string;
+              importCount: {
+                  imported: number;
+                  updated: number;
+                  ignored: number;
+                  deleted: number;
+              };
+              enrollments: {
+                  responseType: "ImportSummaries";
+                  status: "ERROR" | "SUCCESS";
+                  imported: number;
+                  updated: number;
+                  deleted: number;
+                  ignored: number;
+                  total: number;
+              };
+          }
+    >;
+}