diff --git a/lib/address.js b/lib/address.js
index 64742f8a0..75463b40c 100644
--- a/lib/address.js
+++ b/lib/address.js
@@ -26,13 +26,22 @@ function Address (faker) {
     return Helpers.replaceSymbols(format);
   }
 
-
+  /**
+   * Generates random zipcode from state abbreviation. If state abbreviation is
+   * not specified, a random zip code is generated according to the locale's zip format.
+   * Only works for locales with postcode_by_state definition. If a locale does not
+   * have a postcode_by_state definition, a random zip code is generated according
+   * to the locale's zip format.
+   *
+   * @method faker.address.zipCodeByState
+   * @param {String} state
+   */
   this.zipCodeByState = function (state) {
-    var zipFormat = faker.definitions.address.postcode_by_state[state];
-    if (zipFormat) {
-      return this.zipCode(zipFormat);
+    var zipRange = faker.definitions.address.postcode_by_state[state];
+    if (zipRange) {
+      return faker.random.number(zipRange);
     }
-    return undefined;
+    return this.zipCode();
   }
 
   /**
diff --git a/lib/locales/en_US/address/postcode_by_state.js b/lib/locales/en_US/address/postcode_by_state.js
index bf7791119..3bacc4b91 100644
--- a/lib/locales/en_US/address/postcode_by_state.js
+++ b/lib/locales/en_US/address/postcode_by_state.js
@@ -1,54 +1,210 @@
 module["exports"] = {
-  "AL": "350##",
-  "AK": "995##",
-  "AS": "967##",
-  "AZ": "850##",
-  "AR": "717##",
-  "CA": "900##",
-  "CO": "800##",
-  "CT": "061##",
-  "DC": "204##",
-  "DE": "198##",
-  "FL": "322##",
-  "GA": "301##",
-  "HI": "967##",
-  "ID": "832##",
-  "IL": "600##",
-  "IN": "463##",
-  "IA": "510##",
-  "KS": "666##",
-  "KY": "404##",
-  "LA": "701##",
-  "ME": "042##",
-  "MD": "210##",
-  "MA": "026##",
-  "MI": "480##",
-  "MN": "555##",
-  "MS": "387##",
-  "MO": "650##",
-  "MT": "590##",
-  "NE": "688##",
-  "NV": "898##",
-  "NH": "036##",
-  "NJ": "076##",
-  "NM": "880##",
-  "NY": "122##",
-  "NC": "288##",
-  "ND": "586##",
-  "OH": "444##",
-  "OK": "730##",
-  "OR": "979##",
-  "PA": "186##",
-  "RI": "029##",
-  "SC": "299##",
-  "SD": "577##",
-  "TN": "383##",
-  "TX": "798##",
-  "UT": "847##",
-  "VT": "050##",
-  "VA": "222##",
-  "WA": "990##",
-  "WV": "247##",
-  "WI": "549##",
-  "WY": "831##"
-};
+  AK:{
+     min:99501,
+     max:99950
+  },
+  AL:{
+     min:35004,
+     max:36925
+  },
+  AR:{
+     min:71601,
+     max:72959
+  },
+  AZ:{
+     min:85001,
+     max:86556
+  },
+  CA:{
+     min:90001,
+     max:96162
+  },
+  CO:{
+     min:80001,
+     max:81658
+  },
+  CT:{
+     min:6001,
+     max:6389
+  },
+  DC:{
+     min:20001,
+     max:20039
+  },
+  DE:{
+     min:19701,
+     max:19980
+  },
+  FL:{
+     min:32004,
+     max:34997
+  },
+  GA:{
+     min:30001,
+     max:31999
+  },
+  HI:{
+     min:96701,
+     max:96898
+  },
+  IA:{
+     min:50001,
+     max:52809
+  },
+  ID:{
+     min:83201,
+     max:83876
+  },
+  IL:{
+     min:60001,
+     max:62999
+  },
+  IN:{
+     min:46001,
+     max:47997
+  },
+  KS:{
+     min:66002,
+     max:67954
+  },
+  KY:{
+     min:40003,
+     max:42788
+  },
+  LA:{
+     min:70001,
+     max:71232
+  },
+  MA:{
+     min:1001,
+     max:2791
+  },
+  MD:{
+     min:20331,
+     max:20331
+  },
+  ME:{
+     min:3901,
+     max:4992
+  },
+  MI:{
+     min:48001,
+     max:49971
+  },
+  MN:{
+     min:55001,
+     max:56763
+  },
+  MO:{
+     min:63001,
+     max:65899
+  },
+  MS:{
+     min:38601,
+     max:39776
+  },
+  MT:{
+     min:59001,
+     max:59937
+  },
+  NC:{
+     min:27006,
+     max:28909
+  },
+  ND:{
+     min:58001,
+     max:58856
+  },
+  NE:{
+     min:68001,
+     max:68118
+  },
+  NH:{
+     min:3031,
+     max:3897
+  },
+  NJ:{
+     min:7001,
+     max:8989
+  },
+  NM:{
+     min:87001,
+     max:88441
+  },
+  NV:{
+     min:88901,
+     max:89883
+  },
+  NY:{
+     min:6390,
+     max:6390
+  },
+  OH:{
+     min:43001,
+     max:45999
+  },
+  OK:{
+     min:73001,
+     max:73199
+  },
+  OR:{
+     min:97001,
+     max:97920
+  },
+  PA:{
+     min:15001,
+     max:19640
+  },
+  PR:{
+     min:0,
+     max:0
+  },
+  RI:{
+     min:2801,
+     max:2940
+  },
+  SC:{
+     min:29001,
+     max:29948
+  },
+  SD:{
+     min:57001,
+     max:57799
+  },
+  TN:{
+     min:37010,
+     max:38589
+  },
+  TX:{
+     min:73301,
+     max:73301
+  },
+  UT:{
+     min:84001,
+     max:84784
+  },
+  VA:{
+     min:20040,
+     max:20041
+  },
+  VT:{
+     min:5001,
+     max:5495
+  },
+  WA:{
+     min:98001,
+     max:99403
+  },
+  WI:{
+     min:53001,
+     max:54990
+  },
+  WV:{
+     min:24701,
+     max:26886
+  },
+  WY:{
+     min:82001,
+     max:83128
+  }
+}
diff --git a/test/address.unit.js b/test/address.unit.js
index a7bd2e1a8..38ef995af 100644
--- a/test/address.unit.js
+++ b/test/address.unit.js
@@ -252,19 +252,37 @@ describe("address.js", function () {
         });
     });
 
-    describe.only("zipCodeByState()", function () {
+    describe("zipCodeByState()", function () {
         it("returns zipCode valid for specified State", function () {
           faker.locale = "en_US";
-          var state = "IL";
-          var zipCode = faker.address.zipCodeByState(state);
+          var states = ["IL", "GA", "WA"];
 
-          assert.ok(zipCode >= 60000);
-          assert.ok(zipCode <= 60099);
+          var zipCode1 = faker.address.zipCodeByState(states[0]);
+          assert.ok(zipCode1 >= 60001);
+          assert.ok(zipCode1 <= 62999);
+          var zipCode2 = faker.address.zipCodeByState(states[1]);
+          assert.ok(zipCode2 >= 30001);
+          assert.ok(zipCode2 <= 31999);
+          var zipCode3 = faker.address.zipCodeByState(states[2]);
+          assert.ok(zipCode3 >= 98001);
+          assert.ok(zipCode3 <= 99403);
         });
 
-        it("throws error if locale is invalid", function () {
+        it("returns undefined if state is invalid", function () {
+            var state = "XX";
+            sinon.spy(faker.address, 'zipCode');
+            var zipCode = faker.address.zipCodeByState(state);
+            assert.ok(faker.address.zipCode.called);
+            faker.address.zipCode.restore();
         });
-        it("throws error if state is invalid", function () {
+
+        it("returns undefined if state is valid but localeis invalid", function () {
+            faker.locale = "zh_CN";
+            var state = "IL";
+            sinon.spy(faker.address, 'zipCode');
+            var zipCode = faker.address.zipCodeByState(state);
+            assert.ok(faker.address.zipCode.called);
+            faker.address.zipCode.restore();
         });
     });