diff --git a/SabreTools.DatItems.Test/DatItemTests.cs b/SabreTools.DatItems.Test/DatItemTests.cs
index 7572f4c7..4e80ca56 100644
--- a/SabreTools.DatItems.Test/DatItemTests.cs
+++ b/SabreTools.DatItems.Test/DatItemTests.cs
@@ -590,7 +590,112 @@ namespace SabreTools.DatItems.Test
 
         #region GetKey
 
-        // TODO: Implement GetKey tests
+        [Theory]
+        [InlineData(ItemKey.NULL, false, false, "")]
+        [InlineData(ItemKey.NULL, false, true, "")]
+        [InlineData(ItemKey.NULL, true, false, "")]
+        [InlineData(ItemKey.NULL, true, true, "")]
+        [InlineData(ItemKey.Machine, false, false, "0000000000-Machine")]
+        [InlineData(ItemKey.Machine, false, true, "Machine")]
+        [InlineData(ItemKey.Machine, true, false, "0000000000-machine")]
+        [InlineData(ItemKey.Machine, true, true, "machine")]
+        [InlineData(ItemKey.CRC, false, false, "00000000")]
+        [InlineData(ItemKey.CRC, false, true, "00000000")]
+        [InlineData(ItemKey.CRC, true, false, "00000000")]
+        [InlineData(ItemKey.CRC, true, true, "00000000")]
+        [InlineData(ItemKey.MD5, false, false, "d41d8cd98f00b204e9800998ecf8427e")]
+        [InlineData(ItemKey.MD5, false, true, "d41d8cd98f00b204e9800998ecf8427e")]
+        [InlineData(ItemKey.MD5, true, false, "d41d8cd98f00b204e9800998ecf8427e")]
+        [InlineData(ItemKey.MD5, true, true, "d41d8cd98f00b204e9800998ecf8427e")]
+        [InlineData(ItemKey.SHA1, false, false, "da39a3ee5e6b4b0d3255bfef95601890afd80709")]
+        [InlineData(ItemKey.SHA1, false, true, "da39a3ee5e6b4b0d3255bfef95601890afd80709")]
+        [InlineData(ItemKey.SHA1, true, false, "da39a3ee5e6b4b0d3255bfef95601890afd80709")]
+        [InlineData(ItemKey.SHA1, true, true, "da39a3ee5e6b4b0d3255bfef95601890afd80709")]
+        [InlineData(ItemKey.SHA256, false, false, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")]
+        [InlineData(ItemKey.SHA256, false, true, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")]
+        [InlineData(ItemKey.SHA256, true, false, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")]
+        [InlineData(ItemKey.SHA256, true, true, "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855")]
+        [InlineData(ItemKey.SHA384, false, false, "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b")]
+        [InlineData(ItemKey.SHA384, false, true, "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b")]
+        [InlineData(ItemKey.SHA384, true, false, "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b")]
+        [InlineData(ItemKey.SHA384, true, true, "38b060a751ac96384cd9327eb1b1e36a21fdb71114be07434c0cc7bf63f6e1da274edebfe76f65fbd51ad2f14898b95b")]
+        [InlineData(ItemKey.SHA512, false, false, "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e")]
+        [InlineData(ItemKey.SHA512, false, true, "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e")]
+        [InlineData(ItemKey.SHA512, true, false, "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e")]
+        [InlineData(ItemKey.SHA512, true, true, "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e")]
+        [InlineData(ItemKey.SpamSum, false, false, "3::")]
+        [InlineData(ItemKey.SpamSum, false, true, "3::")]
+        [InlineData(ItemKey.SpamSum, true, false, "3::")]
+        [InlineData(ItemKey.SpamSum, true, true, "3::")]
+        public void GetKey_DefaultImplementation(ItemKey bucketedBy, bool lower, bool norename, string expected)
+        {
+            Machine machine = new Machine();
+            machine.SetFieldValue(Models.Metadata.Machine.NameKey, "Machine");
+
+            DatItem datItem = new Blank();
+            datItem.SetFieldValue(DatItem.SourceKey, new Source(0));
+            datItem.SetFieldValue(DatItem.MachineKey, machine);
+
+            string actual = datItem.GetKey(bucketedBy, lower, norename);
+            Assert.Equal(expected, actual);
+        }
+
+        [Theory]
+        [InlineData(ItemKey.NULL, false, false, "")]
+        [InlineData(ItemKey.NULL, false, true, "")]
+        [InlineData(ItemKey.NULL, true, false, "")]
+        [InlineData(ItemKey.NULL, true, true, "")]
+        [InlineData(ItemKey.Machine, false, false, "0000000000-Machine")]
+        [InlineData(ItemKey.Machine, false, true, "Machine")]
+        [InlineData(ItemKey.Machine, true, false, "0000000000-machine")]
+        [InlineData(ItemKey.Machine, true, true, "machine")]
+        [InlineData(ItemKey.CRC, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.CRC, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.CRC, true, false, "deadbeef")]
+        [InlineData(ItemKey.CRC, true, true, "deadbeef")]
+        [InlineData(ItemKey.MD5, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.MD5, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.MD5, true, false, "deadbeef")]
+        [InlineData(ItemKey.MD5, true, true, "deadbeef")]
+        [InlineData(ItemKey.SHA1, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.SHA1, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.SHA1, true, false, "deadbeef")]
+        [InlineData(ItemKey.SHA1, true, true, "deadbeef")]
+        [InlineData(ItemKey.SHA256, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.SHA256, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.SHA256, true, false, "deadbeef")]
+        [InlineData(ItemKey.SHA256, true, true, "deadbeef")]
+        [InlineData(ItemKey.SHA384, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.SHA384, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.SHA384, true, false, "deadbeef")]
+        [InlineData(ItemKey.SHA384, true, true, "deadbeef")]
+        [InlineData(ItemKey.SHA512, false, false, "DEADBEEF")]
+        [InlineData(ItemKey.SHA512, false, true, "DEADBEEF")]
+        [InlineData(ItemKey.SHA512, true, false, "deadbeef")]
+        [InlineData(ItemKey.SHA512, true, true, "deadbeef")]
+        [InlineData(ItemKey.SpamSum, false, false, "BASE64")]
+        [InlineData(ItemKey.SpamSum, false, true, "BASE64")]
+        [InlineData(ItemKey.SpamSum, true, false, "base64")]
+        [InlineData(ItemKey.SpamSum, true, true, "base64")]
+        public void GetKey_CustomImplementation(ItemKey bucketedBy, bool lower, bool norename, string expected)
+        {
+            Machine machine = new Machine();
+            machine.SetFieldValue(Models.Metadata.Machine.NameKey, "Machine");
+
+            DatItem datItem = new Rom();
+            datItem.SetFieldValue(DatItem.SourceKey, new Source(0));
+            datItem.SetFieldValue(DatItem.MachineKey, machine);
+            datItem.SetFieldValue(Models.Metadata.Rom.CRCKey, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.MD5Key, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.SHA1Key, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.SHA256Key, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.SHA384Key, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.SHA512Key, "DEADBEEF");
+            datItem.SetFieldValue(Models.Metadata.Rom.SpamSumKey, "BASE64");
+
+            string actual = datItem.GetKey(bucketedBy, lower, norename);
+            Assert.Equal(expected, actual);
+        }
 
         #endregion
 
diff --git a/SabreTools.DatItems/DatItem.cs b/SabreTools.DatItems/DatItem.cs
index b492bdfc..ca879b6f 100644
--- a/SabreTools.DatItems/DatItem.cs
+++ b/SabreTools.DatItems/DatItem.cs
@@ -364,9 +364,6 @@ namespace SabreTools.DatItems
                     }
 
                     key = $"{sourceString}{machineString}";
-                    if (lower)
-                        key = key.ToLowerInvariant();
-
                     break;
 
                 case ItemKey.MD5:
@@ -396,6 +393,8 @@ namespace SabreTools.DatItems
 
             // Double and triple check the key for corner cases
             key ??= string.Empty;
+            if (lower)
+                key = key.ToLowerInvariant();
 
             return key;
         }
diff --git a/SabreTools.DatItems/Formats/Disk.cs b/SabreTools.DatItems/Formats/Disk.cs
index c1eb5804..3701b6fd 100644
--- a/SabreTools.DatItems/Formats/Disk.cs
+++ b/SabreTools.DatItems/Formats/Disk.cs
@@ -135,6 +135,8 @@ namespace SabreTools.DatItems.Formats
 
             // Double and triple check the key for corner cases
             key ??= string.Empty;
+            if (lower)
+                key = key.ToLowerInvariant();
 
             return key;
         }
diff --git a/SabreTools.DatItems/Formats/File.cs b/SabreTools.DatItems/Formats/File.cs
index 1c6768c8..d9fbe802 100644
--- a/SabreTools.DatItems/Formats/File.cs
+++ b/SabreTools.DatItems/Formats/File.cs
@@ -353,6 +353,8 @@ namespace SabreTools.DatItems.Formats
 
             // Double and triple check the key for corner cases
             key ??= string.Empty;
+            if (lower)
+                key = key.ToLowerInvariant();
 
             return key;
         }
diff --git a/SabreTools.DatItems/Formats/Media.cs b/SabreTools.DatItems/Formats/Media.cs
index 809d4270..a7a6eb00 100644
--- a/SabreTools.DatItems/Formats/Media.cs
+++ b/SabreTools.DatItems/Formats/Media.cs
@@ -104,6 +104,8 @@ namespace SabreTools.DatItems.Formats
 
             // Double and triple check the key for corner cases
             key ??= string.Empty;
+            if (lower)
+                key = key.ToLowerInvariant();
 
             return key;
         }
diff --git a/SabreTools.DatItems/Formats/Rom.cs b/SabreTools.DatItems/Formats/Rom.cs
index 35b9b0a9..95cf1c9b 100644
--- a/SabreTools.DatItems/Formats/Rom.cs
+++ b/SabreTools.DatItems/Formats/Rom.cs
@@ -171,6 +171,8 @@ namespace SabreTools.DatItems.Formats
 
             // Double and triple check the key for corner cases
             key ??= string.Empty;
+            if (lower)
+                key = key.ToLowerInvariant();
 
             return key;
         }