diff --git a/modules/sharethroughBidAdapter.js b/modules/sharethroughBidAdapter.js
index 53cb67c4e6d..ae1fb131966 100644
--- a/modules/sharethroughBidAdapter.js
+++ b/modules/sharethroughBidAdapter.js
@@ -1,7 +1,7 @@
 import { registerBidder } from '../src/adapters/bidderFactory.js';
 import { config } from '../src/config.js';
 import { BANNER, VIDEO } from '../src/mediaTypes.js';
-import { deepAccess, generateUUID, inIframe } from '../src/utils.js';
+import { deepAccess, generateUUID, inIframe, mergeDeep } from '../src/utils.js';
 
 const VERSION = '4.3.0';
 const BIDDER_CODE = 'sharethrough';
@@ -104,6 +104,10 @@ export const sharethroughAdapterSpec = {
 
         const videoRequest = deepAccess(bidReq, 'mediaTypes.video');
 
+        if (bidderRequest.fledgeEnabled && bidReq.mediaTypes.banner) {
+          mergeDeep(impression, { ext: { ae: 1 } }); // ae = auction environment; if this is 1, ad server knows we have a fledge auction
+        }
+
         if (videoRequest) {
           // default playerSize, only change this if we know width and height are properly defined in the request
           let [w, h] = [640, 360];
@@ -116,6 +120,14 @@ export const sharethroughAdapterSpec = {
             [w, h] = videoRequest.playerSize[0];
           }
 
+          const getVideoPlacementValue = (vidReq) => {
+            if (vidReq.plcmt) {
+              return vidReq.placement;
+            } else {
+              return vidReq.context === 'instream' ? 1 : +deepAccess(vidReq, 'placement', 4);
+            }
+          };
+
           impression.video = {
             pos: nullish(videoRequest.pos, 0),
             topframe: inIframe() ? 0 : 1,
@@ -132,7 +144,8 @@ export const sharethroughAdapterSpec = {
             startdelay: nullish(videoRequest.startdelay, 0),
             skipmin: nullish(videoRequest.skipmin, 0),
             skipafter: nullish(videoRequest.skipafter, 0),
-            placement: videoRequest.context === 'instream' ? 1 : +deepAccess(videoRequest, 'placement', 4),
+            placement: getVideoPlacementValue(videoRequest),
+            plcmt: videoRequest.plcmt ? videoRequest.plcmt : null,
           };
 
           if (videoRequest.delivery) impression.video.delivery = videoRequest.delivery;
@@ -179,7 +192,9 @@ export const sharethroughAdapterSpec = {
       return [];
     }
 
-    return body.seatbid[0].bid.map((bid) => {
+    const fledgeAuctionEnabled = body.ext?.auctionConfigs;
+
+    const bidsFromExchange = body.seatbid[0].bid.map((bid) => {
       // Spec: https://docs.prebid.org/dev-docs/bidder-adaptor.html#interpreting-the-response
       const response = {
         requestId: bid.impid,
@@ -219,6 +234,15 @@ export const sharethroughAdapterSpec = {
 
       return response;
     });
+
+    if (fledgeAuctionEnabled) {
+      return {
+        bids: bidsFromExchange,
+        fledgeAuctionConfigs: body.ext?.auctionConfigs || {},
+      };
+    } else {
+      return bidsFromExchange;
+    }
   },
 
   getUserSyncs: (syncOptions, serverResponses) => {
diff --git a/test/spec/modules/sharethroughBidAdapter_spec.js b/test/spec/modules/sharethroughBidAdapter_spec.js
index 6a63ae681e7..1bb6f898b81 100644
--- a/test/spec/modules/sharethroughBidAdapter_spec.js
+++ b/test/spec/modules/sharethroughBidAdapter_spec.js
@@ -585,6 +585,27 @@ describe('sharethrough adapter spec', function () {
 
             expect(videoImp.placement).to.equal(4);
           });
+
+          it('should not override "placement" value if "plcmt" prop is present', () => {
+            // ASSEMBLE
+            const ARBITRARY_PLACEMENT_VALUE = 99;
+            const ARBITRARY_PLCMT_VALUE = 100;
+
+            bidRequests[1].mediaTypes.video.context = 'instream';
+            bidRequests[1].mediaTypes.video.placement = ARBITRARY_PLACEMENT_VALUE;
+
+            // adding "plcmt" property - this should prevent "placement" prop
+            // from getting overridden to 1
+            bidRequests[1].mediaTypes.video['plcmt'] = ARBITRARY_PLCMT_VALUE;
+
+            // ACT
+            const builtRequest = spec.buildRequests(bidRequests, bidderRequest)[1];
+            const videoImp = builtRequest.data.imp[0].video;
+
+            // ASSERT
+            expect(videoImp.placement).to.equal(ARBITRARY_PLACEMENT_VALUE);
+            expect(videoImp.plcmt).to.equal(ARBITRARY_PLCMT_VALUE);
+          });
         });
       });
 
@@ -692,6 +713,22 @@ describe('sharethrough adapter spec', function () {
           expect(openRtbReq.regs.ext.gpp_sid).to.equal(firstPartyData.regs.gpp_sid);
         });
       });
+
+      describe('fledge', () => {
+        it('should attach "ae" as a property to the request if 1) fledge auctions are enabled, and 2) request is display (only supporting display for now)', () => {
+          // ASSEMBLE
+          const EXPECTED_AE_VALUE = 1;
+
+          // ACT
+          bidderRequest['fledgeEnabled'] = true;
+          const builtRequests = spec.buildRequests(bidRequests, bidderRequest);
+          const ACTUAL_AE_VALUE = builtRequests[0].data.imp[0].ext.ae;
+
+          // ASSERT
+          expect(ACTUAL_AE_VALUE).to.equal(EXPECTED_AE_VALUE);
+          expect(builtRequests[1].data.imp[0].ext.ae).to.be.undefined;
+        });
+      });
     });
 
     describe('interpretResponse', function () {