diff --git a/modules/kargoBidAdapter.js b/modules/kargoBidAdapter.js
index 5c3d59bd241..63406bf3ce4 100644
--- a/modules/kargoBidAdapter.js
+++ b/modules/kargoBidAdapter.js
@@ -22,6 +22,10 @@ export const spec = {
       bidIds[bid.bidId] = bid.params.placementId;
       bidSizes[bid.bidId] = bid.sizes;
     });
+    let tdid;
+    if (validBidRequests.length > 0 && validBidRequests[0].userId && validBidRequests[0].userId.tdid) {
+      tdid = validBidRequests[0].userId.tdid;
+    }
     const transformedParams = Object.assign({}, {
       sessionId: spec._getSessionId(),
       timeout: bidderRequest.timeout,
@@ -35,7 +39,7 @@ export const spec = {
       bidIDs: bidIds,
       bidSizes: bidSizes,
       prebidRawBidRequests: validBidRequests
-    }, spec._getAllMetadata());
+    }, spec._getAllMetadata(tdid));
     const encodedParams = encodeURIComponent(JSON.stringify(transformedParams));
     return Object.assign({}, bidderRequest, {
       method: 'GET',
@@ -159,14 +163,18 @@ export const spec = {
     }
   },
 
-  _getUserIds() {
+  _getUserIds(tdid) {
     const crb = spec._getCrb();
-    return {
+    const userIds = {
       kargoID: crb.userId,
       clientID: crb.clientId,
       crbIDs: crb.syncIds || {},
       optOut: crb.optOut
     };
+    if (tdid) {
+      userIds.tdID = tdid;
+    }
+    return userIds;
   },
 
   _getClientId() {
@@ -174,9 +182,9 @@ export const spec = {
     return crb.clientId;
   },
 
-  _getAllMetadata() {
+  _getAllMetadata(tdid) {
     return {
-      userIDs: spec._getUserIds(),
+      userIDs: spec._getUserIds(tdid),
       krux: spec._getKrux(),
       pageURL: window.location.href,
       rawCRB: spec._readCookie('krg_crb'),
diff --git a/test/spec/modules/kargoBidAdapter_spec.js b/test/spec/modules/kargoBidAdapter_spec.js
index a6779f518a0..92f68fd9b91 100644
--- a/test/spec/modules/kargoBidAdapter_spec.js
+++ b/test/spec/modules/kargoBidAdapter_spec.js
@@ -58,6 +58,9 @@ describe('kargo adapter tests', function () {
             placementId: 'foo'
           },
           bidId: 1,
+          userId: {
+            tdid: 'fake-tdid'
+          },
           sizes: [[320, 50], [300, 250], [300, 600]]
         },
         {
@@ -239,6 +242,7 @@ describe('kargo adapter tests', function () {
         userIDs: {
           kargoID: '5f108831-302d-11e7-bf6b-4595acd3bf6c',
           clientID: '2410d8f2-c111-4811-88a5-7b5e190e475f',
+          tdID: 'fake-tdid',
           crbIDs: {
             2: '82fa2555-5969-4614-b4ce-4dcf1080e9f9',
             16: 'VoxIk8AoJz0AAEdCeyAAAAC2&502',
@@ -267,6 +271,9 @@ describe('kargo adapter tests', function () {
             params: {
               placementId: 'foo'
             },
+            userId: {
+              tdid: 'fake-tdid'
+            },
             sizes: [[320, 50], [300, 250], [300, 600]]
           },
           {
@@ -292,6 +299,7 @@ describe('kargo adapter tests', function () {
         base.userIDs = {
           crbIDs: {}
         };
+        delete base.prebidRawBidRequests[0].userId.tdid;
       }
 
       if (excludeKrux) {
@@ -304,8 +312,12 @@ describe('kargo adapter tests', function () {
       return base;
     }
 
-    function testBuildRequests(expected) {
-      var request = spec.buildRequests(bids, {timeout: 200, foo: 'bar'});
+    function testBuildRequests(excludeTdid, expected) {
+      var clonedBids = JSON.parse(JSON.stringify(bids));
+      if (excludeTdid) {
+        delete clonedBids[0].userId.tdid;
+      }
+      var request = spec.buildRequests(clonedBids, {timeout: 200, foo: 'bar'});
       expected.sessionId = getSessionId();
       sessionIds.push(expected.sessionId);
       var krakenParams = JSON.parse(decodeURIComponent(request.data.slice(5)));
@@ -330,23 +342,23 @@ describe('kargo adapter tests', function () {
       initializeKruxUser();
       initializeKruxSegments();
       initializeKrgCrb();
-      testBuildRequests(getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
+      testBuildRequests(false, getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
     });
 
     it('works when all params and cookies are correctly set but no localstorage', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeKrgCrb(true);
-      testBuildRequests(getExpectedKrakenParams(undefined, undefined, null, getKrgCrbOldStyle()));
+      testBuildRequests(false, getExpectedKrakenParams(undefined, undefined, null, getKrgCrbOldStyle()));
     });
 
     it('gracefully handles nothing being set', function() {
-      testBuildRequests(getExpectedKrakenParams(true, true, null, null));
+      testBuildRequests(true, getExpectedKrakenParams(true, true, null, null));
     });
 
     it('gracefully handles browsers without localStorage', function() {
       simulateNoLocalStorage();
-      testBuildRequests(getExpectedKrakenParams(true, true, null, null));
+      testBuildRequests(true, getExpectedKrakenParams(true, true, null, null));
     });
 
     it('handles empty yet valid Kargo CRB', function() {
@@ -354,49 +366,49 @@ describe('kargo adapter tests', function () {
       initializeKruxSegments();
       initializeEmptyKrgCrb();
       initializeEmptyKrgCrbCookie();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, getEmptyKrgCrb(), getEmptyKrgCrbOldStyle()));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, getEmptyKrgCrb(), getEmptyKrgCrbOldStyle()));
     });
 
     it('handles broken Kargo CRBs where base64 encoding is invalid', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType1();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, getInvalidKrgCrbType1(), null));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, getInvalidKrgCrbType1(), null));
     });
 
     it('handles broken Kargo CRBs where top level JSON is invalid on cookie', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType1Cookie();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType1()));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType1()));
     });
 
     it('handles broken Kargo CRBs where decoded JSON is invalid', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType2();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, getInvalidKrgCrbType2(), null));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, getInvalidKrgCrbType2(), null));
     });
 
     it('handles broken Kargo CRBs where inner base 64 is invalid on cookie', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType2Cookie();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType2OldStyle()));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType2OldStyle()));
     });
 
     it('handles broken Kargo CRBs where inner JSON is invalid on cookie', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType3Cookie();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType3OldStyle()));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType3OldStyle()));
     });
 
     it('handles broken Kargo CRBs where inner JSON is falsey', function() {
       initializeKruxUser();
       initializeKruxSegments();
       initializeInvalidKrgCrbType4Cookie();
-      testBuildRequests(getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType4OldStyle()));
+      testBuildRequests(true, getExpectedKrakenParams(true, undefined, null, getInvalidKrgCrbType4OldStyle()));
     });
 
     it('handles a non-existant currency object on the config', function() {
@@ -404,7 +416,7 @@ describe('kargo adapter tests', function () {
       initializeKruxUser();
       initializeKruxSegments();
       initializeKrgCrb();
-      testBuildRequests(getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
+      testBuildRequests(false, getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
     });
 
     it('handles no ad server currency being set on the currency object in the config', function() {
@@ -412,7 +424,7 @@ describe('kargo adapter tests', function () {
       initializeKruxUser();
       initializeKruxSegments();
       initializeKrgCrb();
-      testBuildRequests(getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
+      testBuildRequests(false, getExpectedKrakenParams(undefined, undefined, getKrgCrb(), getKrgCrbOldStyle()));
     });
   });