diff --git a/src/examples/Program.cs b/src/examples/Program.cs
index 938b489..5b1be8e 100644
--- a/src/examples/Program.cs
+++ b/src/examples/Program.cs
@@ -16,6 +16,7 @@ private static void Main()
 			USReverseGeoExample.Run();
 			USEnrichmentPropertyExample.Run();
 			USEnrichmentGeoReferenceExample.Run();
+			USEnrichmentSecondaryExample.Run();
 			USEnrichmentUniversalExample.Run();
 		}
 	}
diff --git a/src/examples/USEnrichmentSecondaryExample.cs b/src/examples/USEnrichmentSecondaryExample.cs
new file mode 100644
index 0000000..e2ff451
--- /dev/null
+++ b/src/examples/USEnrichmentSecondaryExample.cs
@@ -0,0 +1,112 @@
+namespace Examples
+{
+	using System;
+	using System.Net;
+	using System.Collections.Generic;
+	using System.IO;
+    using System.Linq;
+    using SmartyStreets;
+	using SmartyStreets.USEnrichmentApi;
+    using System.Reflection;
+    using System.Text;
+
+	internal static class USEnrichmentSecondaryExample
+	{
+		public static void Run()
+		{
+            // specifies the TLS protocoll to use - this is TLS 1.2
+            const SecurityProtocolType tlsProtocol1_2 = (SecurityProtocolType)3072;
+
+            // var authId = "Your SmartyStreets Auth ID here";
+            // var authToken = "Your SmartyStreets Auth Token here";
+
+            // We recommend storing your keys in environment variables instead---it's safer!
+            var authId = Environment.GetEnvironmentVariable("SMARTY_AUTH_ID");
+			var authToken = Environment.GetEnvironmentVariable("SMARTY_AUTH_TOKEN");
+			ServicePointManager.SecurityProtocol = tlsProtocol1_2;
+
+			var client = new ClientBuilder(authId, authToken).BuildUsEnrichmentApiClient();
+			
+            // See the US Enrichment API documenation for all available datasets and data subsets https://www.smarty.com/docs/cloud/us-address-enrichment-api#data-sets
+            SmartyStreets.USEnrichmentApi.Secondary.Result[] results = null;
+            var lookup = new SmartyStreets.USEnrichmentApi.Secondary.Lookup("325023201");
+            // Options available for Lookup
+            // lookup.SetEtag("HAYDKMJXHA4DKNA");
+
+            try {
+                results = client.SendSecondaryLookup(lookup);
+            }
+            catch (NotModifiedException ex) {
+                Console.WriteLine(ex.Message); // The Etag value provided represents the latest version of the requested record
+            }
+            catch (Exception ex) {
+                Console.WriteLine(ex.Message + ex.StackTrace);
+            }
+            
+            if (results is not null) {
+                foreach (SmartyStreets.USEnrichmentApi.Secondary.Result result in results) {
+                    PrintResult(result);
+                    if (result.Aliases is not null) {
+                        Console.WriteLine("Aliases: {");
+                        foreach (SmartyStreets.USEnrichmentApi.Secondary.Aliases alias in result.Aliases) {
+                            PrintResult(alias);
+                            Console.WriteLine();
+                        }
+                        Console.WriteLine("}\n");
+                    }
+                    Console.WriteLine("Secondaries: {");
+                    foreach (SmartyStreets.USEnrichmentApi.Secondary.Secondaries secondary in result.Secondaries) {
+                        PrintResult(secondary);
+                        Console.WriteLine();
+                    }
+                    Console.WriteLine("}\n");
+                }
+            }
+            else {
+                Console.WriteLine("Result was null");
+            }
+
+            SmartyStreets.USEnrichmentApi.Secondary.Count.Result[] countResults = null;
+            var countLookup = new SmartyStreets.USEnrichmentApi.Secondary.Count.Lookup("325023201");
+            // Options available for Lookup
+            // lookup.SetEtag("HAYDKMJXHA4DKNA");
+
+            try {
+                countResults = client.SendSecondaryCountLookup(countLookup);
+            }
+            catch (NotModifiedException ex) {
+                Console.WriteLine(ex.Message); // The Etag value provided represents the latest version of the requested record
+            }
+            catch (Exception ex) {
+                Console.WriteLine(ex.Message + ex.StackTrace);
+            }
+            
+            if (countResults is not null) {
+                Console.WriteLine("Count: {");
+                foreach (SmartyStreets.USEnrichmentApi.Secondary.Count.Result result in countResults) {
+                    PrintResult(result);
+                }
+                Console.WriteLine("}");
+            }
+            else {
+                Console.WriteLine("Result was null");
+            }
+        }
+
+
+        private static void PrintResult(object obj){
+            Type type = obj.GetType();
+            
+            foreach (PropertyInfo property in type.GetProperties()) {
+                if (property.Name == "RootAddress") {
+                    Console.WriteLine("Root Address: {");
+                    PrintResult(property.GetValue(obj, null));
+                    Console.WriteLine("}\n");
+                }
+                else if (property.GetValue(obj, null) is not null && property.Name != "Aliases" && property.Name != "Secondaries") {
+                    Console.WriteLine($"{property.Name}: {property.GetValue(obj, null)}");
+                }
+            }
+        }
+	}
+}
diff --git a/src/sdk/USEnrichmentApi/Client.cs b/src/sdk/USEnrichmentApi/Client.cs
index 69ffb83..f676fe7 100644
--- a/src/sdk/USEnrichmentApi/Client.cs
+++ b/src/sdk/USEnrichmentApi/Client.cs
@@ -53,6 +53,32 @@ public GeoReference.Result[] SendGeoReferenceLookup(GeoReference.Lookup lookup)
 			return lookup.GetResults();
 		}
 
+		public Secondary.Result[] SendSecondaryLookup(string smartyKey)
+		{
+			Secondary.Lookup lookup = new Secondary.Lookup(smartyKey);
+			Send(lookup);
+			return lookup.GetResults();
+		}
+
+		public Secondary.Result[] SendSecondaryLookup(Secondary.Lookup lookup)
+		{
+			Send(lookup);
+			return lookup.GetResults();
+		}
+
+		public Secondary.Count.Result[] SendSecondaryCountLookup(string smartyKey)
+		{
+			Secondary.Count.Lookup lookup = new Secondary.Count.Lookup(smartyKey);
+			Send(lookup);
+			return lookup.GetResults();
+		}
+
+		public Secondary.Count.Result[] SendSecondaryCountLookup(Secondary.Count.Lookup lookup)
+		{
+			Send(lookup);
+			return lookup.GetResults();
+		}
+
 		public byte[] SendUniversalLookup(Universal.Lookup lookup)
 		{
 			Send(lookup);
diff --git a/src/sdk/USEnrichmentApi/Secondary/Aliases.cs b/src/sdk/USEnrichmentApi/Secondary/Aliases.cs
new file mode 100644
index 0000000..237e1b0
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Aliases.cs
@@ -0,0 +1,38 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary
+{
+    using System.Runtime.Serialization;
+
+	[DataContract]
+    public class Aliases
+    {
+        [DataMember(Name = "smarty_key")]
+        public string SmartyKey { get; set; }
+        
+        [DataMember(Name = "primary_number")]
+        public string PrimaryNumber { get; set; }
+
+        [DataMember(Name = "street_predirection")]
+        public string StreetPredirection { get; set; }
+        
+        [DataMember(Name = "street_name")]
+        public string StreetName { get; set; }
+
+        [DataMember(Name = "street_suffix")]
+        public string StreetSuffix { get; set; }
+
+        [DataMember(Name = "street_postdirection")]
+        public string StreetPostdirection { get; set; }
+
+        [DataMember(Name = "city_name")]
+        public string CityName { get; set; }
+
+        [DataMember(Name = "state_abbreviation")]
+        public string StateAbbreviation { get; set; }
+
+        [DataMember(Name = "zipcode")]
+        public string Zipcode { get; set; }
+
+        [DataMember(Name = "plus4_code")]
+        public string Plus4Code { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/Count/Lookup.cs b/src/sdk/USEnrichmentApi/Secondary/Count/Lookup.cs
new file mode 100644
index 0000000..a0972c7
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Count/Lookup.cs
@@ -0,0 +1,31 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary.Count
+{
+    using System;
+    using System.IO;
+    using SmartyStreets.USEnrichmentApi.Secondary;
+
+    public class Lookup : SmartyStreets.USEnrichmentApi.Lookup
+    {
+        private Result[] results;
+
+        public Lookup(string smartyKey) : base(smartyKey, "secondary", "count")
+        {
+        }
+
+        public Result[] GetResults()
+        {
+            return results;
+        }
+
+        public void SetResults(Result[] results)
+        {
+            this.results = results;
+        }
+
+        public override void DeserializeAndSetResults(SmartyStreets.ISerializer serializer, Stream payload)
+        {
+            this.results = serializer.Deserialize<Result[]>(payload);
+            this.results[0].Etag = this.GetEtag();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/Count/Result.cs b/src/sdk/USEnrichmentApi/Secondary/Count/Result.cs
new file mode 100644
index 0000000..87a778b
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Count/Result.cs
@@ -0,0 +1,17 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary.Count
+{
+    using System.Runtime.Serialization;
+
+	[DataContract]
+    public class Result
+    {
+        [DataMember(Name = "smarty_key")]
+        public string SmartyKey { get; set; }
+
+        [DataMember(Name = "etag")]
+        public string Etag { get; set; }
+
+        [DataMember(Name = "count")]
+        public string count { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/Lookup.cs b/src/sdk/USEnrichmentApi/Secondary/Lookup.cs
new file mode 100644
index 0000000..5747834
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Lookup.cs
@@ -0,0 +1,31 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary
+{
+    using System;
+    using System.IO;
+    using SmartyStreets.USEnrichmentApi.Secondary;
+
+    public class Lookup : SmartyStreets.USEnrichmentApi.Lookup
+    {
+        private Result[] results;
+
+        public Lookup(string smartyKey) : base(smartyKey, "secondary", "")
+        {
+        }
+
+        public Result[] GetResults()
+        {
+            return results;
+        }
+
+        public void SetResults(Result[] results)
+        {
+            this.results = results;
+        }
+
+        public override void DeserializeAndSetResults(SmartyStreets.ISerializer serializer, Stream payload)
+        {
+            this.results = serializer.Deserialize<Result[]>(payload);
+            this.results[0].Etag = this.GetEtag();
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/Result.cs b/src/sdk/USEnrichmentApi/Secondary/Result.cs
new file mode 100644
index 0000000..1b730b7
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Result.cs
@@ -0,0 +1,23 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary
+{
+    using System.Runtime.Serialization;
+
+	[DataContract]
+    public class Result
+    {
+        [DataMember(Name = "smarty_key")]
+        public string SmartyKey { get; set; }
+
+        [DataMember(Name = "etag")]
+        public string Etag { get; set; }
+
+        [DataMember(Name = "root_address")]
+        public RootAddress RootAddress { get; set; }
+
+        [DataMember(Name = "aliases")]
+        public Aliases[] Aliases { get; set; }
+
+        [DataMember(Name = "secondaries")]
+        public Secondaries[] Secondaries { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/RootAddress.cs b/src/sdk/USEnrichmentApi/Secondary/RootAddress.cs
new file mode 100644
index 0000000..5e01333
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/RootAddress.cs
@@ -0,0 +1,41 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary
+{
+    using System.Runtime.Serialization;
+
+	[DataContract]
+    public class RootAddress
+    {
+        [DataMember(Name = "secondary_count")]
+        public string SecondaryCount { get; set; }
+
+        [DataMember(Name = "smarty_key")]
+        public string SmartyKey { get; set; }
+        
+        [DataMember(Name = "primary_number")]
+        public string PrimaryNumber { get; set; }
+
+        [DataMember(Name = "street_predirection")]
+        public string StreetPredirection { get; set; }
+        
+        [DataMember(Name = "street_name")]
+        public string StreetName { get; set; }
+
+        [DataMember(Name = "street_suffix")]
+        public string StreetSuffix { get; set; }
+
+        [DataMember(Name = "street_postdirection")]
+        public string StreetPostdirection { get; set; }
+
+        [DataMember(Name = "city_name")]
+        public string CityName { get; set; }
+
+        [DataMember(Name = "state_abbreviation")]
+        public string StateAbbreviation { get; set; }
+
+        [DataMember(Name = "zipcode")]
+        public string Zipcode { get; set; }
+
+        [DataMember(Name = "plus4_code")]
+        public string Plus4Code { get; set; }
+    }
+}
\ No newline at end of file
diff --git a/src/sdk/USEnrichmentApi/Secondary/Secondaries.cs b/src/sdk/USEnrichmentApi/Secondary/Secondaries.cs
new file mode 100644
index 0000000..71e0ae2
--- /dev/null
+++ b/src/sdk/USEnrichmentApi/Secondary/Secondaries.cs
@@ -0,0 +1,20 @@
+namespace SmartyStreets.USEnrichmentApi.Secondary
+{
+    using System.Runtime.Serialization;
+
+	[DataContract]
+    public class Secondaries
+    {
+        [DataMember(Name = "smarty_key")]
+        public string SmartyKey { get; set; }
+        
+        [DataMember(Name = "secondary_designator")]
+        public string SecondaryDesignator { get; set; }
+
+        [DataMember(Name = "secondary_number")]
+        public string SecondaryNumber { get; set; }
+        
+        [DataMember(Name = "plus4_code")]
+        public string Plus4Code { get; set; }
+    }
+}
\ No newline at end of file