diff --git a/src/program/ProgramInit.js b/src/program/ProgramInit.js
index e363c9f..9d76a69 100644
--- a/src/program/ProgramInit.js
+++ b/src/program/ProgramInit.js
@@ -56,14 +56,49 @@ module.exports = Class( 'ProgramInit',
     {
         const defaults = program.defaults || {};
 
-        // initialize to an array with a single element of the default value
-        return Promise.resolve(
-            Object.keys( defaults ).reduce(
-                ( data, key ) => ( data[ key ] === undefined )
-                    ? ( data[ key ] = [ defaults[ key ] ], data )
-                    : data,
-                doc_data || {}
-            )
-        );
+        var data = {},
+            groups = program.meta.groups;
+
+        Object.keys( program.groupExclusiveFields ).forEach( function( group, index )
+        {
+            var length = program.groupExclusiveFields[ group ].length;
+
+            while ( length-- )
+            {
+                var field = program.groupExclusiveFields[ group ][ length ],
+                    defaultValue;
+
+                if ( defaults.hasOwnProperty(field) )
+                {
+                    defaultValue = defaults[ field ];
+                    // Initialize with existing document data if any
+                    data[ field ] = doc_data[ field ] ? doc_data[ field ] : [];
+
+                    // If no document data, initialize with default value
+                    if ( !doc_data[ field ] )
+                    {
+                        data[ field ][ 0 ] = defaultValue;
+                    }
+
+                    // If min rows on the group is greater than the data
+                    // currently in the bucket, then populate the rest
+                    // of the data with the default data until the
+                    // arrays are the same length
+                    if ( groups.hasOwnProperty( group ) &&
+                         data[ field ].length < groups[ group ].min )
+                    {
+                        var index = data[ field ].length;
+
+                        while ( index < groups[ group ].min )
+                        {
+                            data[ field ][ index ] = defaultValue;
+                            index++;
+                        }
+                    }
+                }
+            }
+        });
+
+        return Promise.resolve( data );
     },
 } );
diff --git a/test/program/ProgramInitTest.js b/test/program/ProgramInitTest.js
index 581a5c4..fe65914 100644
--- a/test/program/ProgramInitTest.js
+++ b/test/program/ProgramInitTest.js
@@ -34,6 +34,12 @@ describe( 'ProgramInit', () =>
         {
             label:    "initializes defaults",
             defaults: { a: "one", b: "two" },
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {
+                Something: [ "a", "b" ]
+            },
             doc_data: {},
             expected: {
                 a: [ "one" ],
@@ -43,18 +49,33 @@ describe( 'ProgramInit', () =>
         {
             label:    "does nothing with no data or defaults",
             defaults: {},
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {},
             doc_data: {},
             expected: {},
         },
         {
             label:    "produces empty object given undefined data",
             defaults: {},
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {},
             doc_data: undefined,
             expected: {},
         },
         {
             label:    "keeps existing data with defaults",
             defaults: { foo: "init" },
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ],
+                SomethingElse: [ "bar" ]
+            },
             doc_data: { bar: [ "baz" ] },
             expected: {
                 foo: [ "init" ],
@@ -64,6 +85,12 @@ describe( 'ProgramInit', () =>
         {
             label:    "keeps existing doc data with no defaults",
             defaults: {},
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ],
+            },
             doc_data: { foo: [ "bar" ] },
             expected: {
                 foo: [ "bar" ],
@@ -72,12 +99,74 @@ describe( 'ProgramInit', () =>
         {
             label:    "does not overwrite existing data with defaults",
             defaults: { foo: "init" },
+            meta: {
+                groups: {}
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ]
+            },
             doc_data: { foo: [ "bar" ] },
             expected: {
                 foo: [ "bar" ],
             },
         },
-    ].forEach( ({ label, doc_data, id, defaults, expected }) =>
+        {
+            label:    "does not overwrite existing data with defaults and multiple rows",
+            defaults: { foo: "init" },
+            meta: {
+                groups: {
+                    Something: {
+                        min: 3
+                    }
+                }
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ]
+            },
+            doc_data: { foo: [ "bar", "baz", "test" ] },
+            expected: {
+                foo: [ "bar", "baz", "test" ],
+            },
+        },
+        {
+            label:    "initializes with default bucket data",
+            defaults: { foo: "init" },
+            meta: {
+                groups: {
+                    Something: {
+                        min: 5
+                    }
+                }
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ]
+            },
+            doc_data: {},
+            expected: {
+                foo: [ "init", "init", "init", "init", "init" ],
+            },
+        },
+        {
+            label:    "fix missing bucket data values",
+            defaults: { foo: "init" },
+            meta: {
+                groups: {
+                    Something: {
+                        min: 5
+                    }
+                }
+            },
+            groupExclusiveFields: {
+                Something: [ "foo" ]
+            },
+            doc_data: {
+                foo: [ "1", "2", "3", "4" ],
+            },
+            expected: {
+                foo: [ "1", "2", "3", "4", "init" ],
+            },
+        },
+    ].forEach( ({ label, doc_data, id, defaults, meta, groupExclusiveFields, expected }) =>
     {
         it( label, () =>
         {
@@ -86,6 +175,8 @@ describe( 'ProgramInit', () =>
             const program = {
                 id:       "foo",
                 defaults: defaults,
+                meta: meta,
+                groupExclusiveFields : groupExclusiveFields
             };
 
             return expect( sut.init( program, doc_data ) )