diff --git a/modules/gumgumBidAdapter.js b/modules/gumgumBidAdapter.js
new file mode 100644
index 00000000000..2627b7417f5
--- /dev/null
+++ b/modules/gumgumBidAdapter.js
@@ -0,0 +1,170 @@
+import * as utils from 'src/utils'
+
+import { config } from 'src/config'
+import { registerBidder } from 'src/adapters/bidderFactory'
+
+const BIDDER_CODE = 'gumgum'
+const ALIAS_BIDDER_CODE = ['gg']
+const BID_ENDPOINT = `https://g2.gumgum.com/hbid/imp`
+const DT_CREDENTIALS = { member: 'YcXr87z2lpbB' }
+const TIME_TO_LIVE = 60
+let browserParams = {};
+
+// TODO: potential 0 values for browserParams sent to ad server
+function _getBrowserParams() {
+  let topWindow
+  let topScreen
+  if (browserParams.vw) {
+    // we've already initialized browserParams, just return it.
+    return browserParams
+  }
+
+  try {
+    topWindow = global.top;
+    topScreen = topWindow.screen;
+  } catch (error) {
+    utils.logError(error);
+    return browserParams
+  }
+
+  browserParams = {
+    vw: topWindow.innerWidth,
+    vh: topWindow.innerHeight,
+    sw: topScreen.width,
+    sh: topScreen.height,
+    pu: utils.getTopWindowUrl(),
+    ce: utils.cookiesAreEnabled(),
+    dpr: topWindow.devicePixelRatio || 1
+  }
+  return browserParams
+}
+
+function getWrapperCode(wrapper, data) {
+  return wrapper.replace('AD_JSON', window.btoa(JSON.stringify(data)))
+}
+
+// TODO: use getConfig()
+function _getDigiTrustQueryParams() {
+  function getDigiTrustId () {
+    var digiTrustUser = (window.DigiTrust && window.DigiTrust.getUser) ? window.DigiTrust.getUser(DT_CREDENTIALS) : {};
+    return (digiTrustUser && digiTrustUser.success && digiTrustUser.identity) || '';
+  };
+
+  let digiTrustId = getDigiTrustId();
+  // Verify there is an ID and this user has not opted out
+  if (!digiTrustId || (digiTrustId.privacy && digiTrustId.privacy.optout)) {
+    return {};
+  }
+  return {
+    'dt': digiTrustId.id
+  };
+}
+
+/**
+ * Determines whether or not the given bid request is valid.
+ *
+ * @param {BidRequest} bid The bid params to validate.
+ * @return boolean True if this is a valid bid, and false otherwise.
+ */
+function isBidRequestValid (bid) {
+  const {
+    params,
+    adUnitCode
+  } = bid;
+
+  switch (true) {
+    case !!(params.inScreen): break;
+    case !!(params.inSlot): break;
+    default:
+      utils.logWarn(`[GumGum] No product selected for the placement ${adUnitCode}, please check your implementation.`);
+      return false;
+  }
+  return true;
+}
+
+/**
+ * Make a server request from the list of BidRequests.
+ *
+ * @param {validBidRequests[]} - an array of bids
+ * @return ServerRequest Info describing the request to the server.
+ */
+function buildRequests (validBidRequests) {
+  const bids = [];
+  utils._each(validBidRequests, bidRequest => {
+    const timeout = config.getConfig('bidderTimeout');
+    const {
+      bidId,
+      params = {},
+      transactionId
+    } = bidRequest;
+    const data = {}
+
+    if (params.inScreen) {
+      data.t = params.inScreen;
+      data.pi = 2;
+    }
+    if (params.inSlot) {
+      data.si = parseInt(params.inSlot, 10);
+      data.pi = 3;
+    }
+
+    bids.push({
+      id: bidId,
+      tmax: timeout,
+      tId: transactionId,
+      pi: data.pi,
+      sizes: bidRequest.sizes,
+      url: BID_ENDPOINT,
+      method: 'GET',
+      data: Object.assign(data, _getBrowserParams(), _getDigiTrustQueryParams())
+    })
+  });
+  return bids;
+}
+
+/**
+ * Unpack the response from the server into a list of bids.
+ *
+ * @param {*} serverResponse A successful response from the server.
+ * @return {Bid[]} An array of bids which were nested inside the server.
+ */
+function interpretResponse (serverResponse, bidRequest) {
+  const bidResponses = []
+  const serverResponseBody = serverResponse.body
+  const {
+    ad: {
+      price: cpm,
+      id: creativeId,
+      markup
+    },
+    cw: wrapper
+  } = serverResponseBody
+  let isTestUnit = (bidRequest.data && bidRequest.data.pi === 3 && bidRequest.data.si === 9)
+  let [width, height] = utils.parseSizesInput(bidRequest.sizes)[0].split('x')
+
+  if (creativeId) {
+    bidResponses.push({
+      // dealId: DEAL_ID,
+      // referrer: REFERER,
+      ad: wrapper ? getWrapperCode(wrapper, Object.assign({}, serverResponseBody, { bidRequest })) : markup,
+      cpm: isTestUnit ? 0.1 : cpm,
+      creativeId,
+      currency: 'USD',
+      height,
+      netRevenue: true,
+      requestId: bidRequest.id,
+      ttl: TIME_TO_LIVE,
+      width
+    })
+  }
+  return bidResponses
+}
+
+export const spec = {
+  code: BIDDER_CODE,
+  aliases: ALIAS_BIDDER_CODE,
+  isBidRequestValid,
+  buildRequests,
+  interpretResponse
+}
+registerBidder(spec)
diff --git a/modules/gumgumBidAdapter.md b/modules/gumgumBidAdapter.md
new file mode 100644
index 00000000000..500c2a49e3b
--- /dev/null
+++ b/modules/gumgumBidAdapter.md
@@ -0,0 +1,40 @@
+# Overview
+
+```
+Module Name: GumGum Bidder Adapter
+Module Type: Bidder Adapter
+Maintainer: engineering@gumgum.com
+```
+
+# Description
+
+GumGum adapter for Prebid.js 1.0
+
+# Test Parameters
+```
+var adUnits = [
+  {
+    code: 'test-div',
+    sizes: [[300, 250]],
+    bids: [
+      {
+        bidder: 'gumgum',
+        params: {
+          inSlot: '9' // GumGum Slot ID given to the client
+        }
+      }
+    ]
+  },{
+    code: 'test-div',
+    sizes: [[300, 50]],
+    bids: [
+      {
+        bidder: 'gumgum',
+        params: {
+          inScreen: 'ggumtest' // GumGum Zone ID given to the client
+        }
+      }
+    ]
+  }
+];
+```
diff --git a/test/spec/modules/gumgumBidAdapter_spec.js b/test/spec/modules/gumgumBidAdapter_spec.js
new file mode 100644
index 00000000000..30627d4d12d
--- /dev/null
+++ b/test/spec/modules/gumgumBidAdapter_spec.js
@@ -0,0 +1,138 @@
+import { expect } from 'chai';
+import { newBidder } from 'src/adapters/bidderFactory';
+import { spec } from 'modules/gumgumBidAdapter';
+
+const ENDPOINT = 'https://g2.gumgum.com/hbid/imp';
+
+describe('gumgumAdapter', () => {
+  const adapter = newBidder(spec);
+
+  describe('inherited functions', () => {
+    it('exists and is a function', () => {
+      expect(adapter.callBids).to.exist.and.to.be.a('function');
+    });
+  });
+
+  describe('isBidRequestValid', () => {
+    let bid = {
+      'bidder': 'gumgum',
+      'params': {
+        'inScreen': '10433394'
+      },
+      'adUnitCode': 'adunit-code',
+      'sizes': [[300, 250], [300, 600]],
+      'bidId': '30b31c1838de1e',
+      'bidderRequestId': '22edbae2733bf6',
+      'auctionId': '1d1a030790a475',
+    };
+
+    it('should return true when required params found', () => {
+      expect(spec.isBidRequestValid(bid)).to.equal(true);
+    });
+
+    it('should return true when required params found', () => {
+      let bid = Object.assign({}, bid);
+      delete bid.params;
+      bid.params = {
+        'inSlot': '789'
+      };
+
+      expect(spec.isBidRequestValid(bid)).to.equal(true);
+    });
+
+    it('should return false when required params are not passed', () => {
+      let bid = Object.assign({}, bid);
+      delete bid.params;
+      bid.params = {
+        'placementId': 0
+      };
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+  });
+
+  describe('buildRequests', () => {
+    let bidRequests = [
+      {
+        'bidder': 'gumgum',
+        'params': {
+          'inSlot': '9'
+        },
+        'adUnitCode': 'adunit-code',
+        'sizes': [[300, 250], [300, 600]],
+        'bidId': '30b31c1838de1e'
+      }
+    ];
+
+    it('sends bid request to ENDPOINT via GET', () => {
+      const requests = spec.buildRequests(bidRequests);
+      const request = requests[0];
+      expect(request.url).to.equal(ENDPOINT);
+      expect(request.method).to.equal('GET');
+      expect(request.id).to.equal('30b31c1838de1e');
+    });
+  })
+
+  describe('interpretResponse', () => {
+    let serverResponse = {
+      'ad': {
+        'id': 29593,
+        'width': 300,
+        'height': 250,
+        'ipd': 2000,
+        'markup': '<html><h3>I am an ad</h3></html>',
+        'ii': true,
+        'du': null,
+        'price': 0,
+        'zi': 0,
+        'impurl': 'http://g2.gumgum.com/ad/view',
+        'clsurl': 'http://g2.gumgum.com/ad/close'
+      },
+      'pag': {
+        't': 'ggumtest',
+        'pvid': 'aa8bbb65-427f-4689-8cee-e3eed0b89eec',
+        'css': 'html { overflow-y: auto }',
+        'js': 'console.log("environment", env);'
+      },
+      'thms': 10000
+    }
+    let bidRequest = {
+      id: 12345,
+      sizes: [[300, 250]],
+      url: ENDPOINT,
+      method: 'GET',
+      pi: 3
+    }
+
+    it('should get correct bid response', () => {
+      let expectedResponse = {
+        'ad': '<html><h3>I am an ad</h3></html>',
+        'cpm': 0,
+        'creativeId': 29593,
+        'currency': 'USD',
+        'height': '250',
+        'netRevenue': true,
+        'requestId': 12345,
+        'width': '300',
+        // dealId: DEAL_ID,
+        // referrer: REFERER,
+        ttl: 60
+      };
+      expect(spec.interpretResponse({ body: serverResponse }, bidRequest)).to.deep.equal([expectedResponse]);
+    });
+
+    it('handles nobid responses', () => {
+      let response = {
+        'ad': {},
+        'pag': {
+          't': 'ggumtest',
+          'pvid': 'aa8bbb65-427f-4689-8cee-e3eed0b89eec',
+          'css': 'html { overflow-y: auto }',
+          'js': 'console.log("environment", env);'
+        },
+        'thms': 10000
+      }
+      let result = spec.interpretResponse({ body: response }, bidRequest);
+      expect(result.length).to.equal(0);
+    });
+  })
+});