diff --git a/CHANGELOG.md b/CHANGELOG.md
index 58de5f1..368d5fc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,11 +11,33 @@
 --->
 
 # Unreleased
+
+## 🚨 Breaking change
+
+`include_data_types` parameter added to `generate_model_yaml` and behavior changed for `generate_source`. Both default to `true`
+and are lowercase to align with the dbt style guide. Scale & precision are **not** included. Previous logic for `generate_source` defaulted to `false` and the resulting data types were uppercase and included scale & precision ([#122](https://github.com/dbt-labs/dbt-codegen/pull/122)).
+
+[Dispatch](https://docs.getdbt.com/reference/dbt-jinja-functions/dispatch) can be used to utilize the column data type formatting of previous versions. Namely, by adding this macro to your project:
+```sql
+{% macro default__data_type_format_source(column) %}
+    {{ return(column.data_type | upper) }}
+{% endmacro %}
+```
+
+And then adding this within `dbt_project.yml`:
+```yaml
+dispatch:
+  - macro_namespace: codegen
+    search_order: ['my_project', 'codegen']
+```
+
+
 ## New features
 - Addition of the [create_base_models](macros/create_base_models.sql)
 This macro generates a series of terminal commands (appended w) bash script which creates a new file in your dbt project based off the results of the [generate_base_model](macros/generate_base_model.sql) macro. Therefore, instead of outputting in the terminal, it will create the file for you.
 - Add `include_data_types` flag to `generate_source` macro ([#76](https://github.com/dbt-labs/dbt-codegen/pull/76))
 - Add `get_models` macro in helper macros. This macro retrieves a list of models with specified prefix at the specified directory. It is designed to make creating yamls for multiple models easier.
+- Add `include_data_types` flag to `generate_model_yaml` macro ([#122](https://github.com/dbt-labs/dbt-codegen/pull/122))
 - Add optional arguments to include database and schema properties in `sources.yml` generated from `generate_source` ([#123](https://github.com/dbt-labs/dbt-codegen/issues/123))
 
 ## Fixes
@@ -28,6 +50,7 @@ This macro generates a series of terminal commands (appended w) bash script whic
 ## Contributors:
 - [@fivetran-joemarkiewicz](https://github.com/fivetran-joemarkiewicz) (#83)
 - [@GSokol](https://github.com/GSokol) (#76)
+- [@linbug](https://github.com/linbug) (#120)
 
 # dbt-codegen v0.9.0
 
diff --git a/README.md b/README.md
index 50056a8..653d1ca 100644
--- a/README.md
+++ b/README.md
@@ -50,7 +50,7 @@ source data is in.
 column names to your source definition.
 * `include_descriptions` (optional, default=False): Whether you want to add 
 description placeholders to your source definition.
-* `include_data_types` (optional, default=False): Whether you want to add data
+* `include_data_types` (optional, default=True): Whether you want to add data
 types to your source columns definitions.
 * `table_pattern` (optional, default='%'): A table prefix / postfix that you
 want to subselect from all available tables within a given schema.
@@ -87,10 +87,16 @@ or
 $ dbt run-operation generate_source --args '{"schema_name": "jaffle_shop", "database_name": "raw", "table_names":["table_1", "table_2"]}'
 ```
 
-Including data types:
+or if you want to include column names and data types:
 
 ```
-$ dbt run-operation generate_source --args '{"schema_name": "jaffle_shop", "generate_columns": "true", "include_data_types": "true"}'
+$ dbt run-operation generate_source --args '{"schema_name": "jaffle_shop", "generate_columns": true}'
+```
+
+or if you want to include column names without data types (the behavior dbt-codegen <= v0.9.0):
+
+```
+$ dbt run-operation generate_source --args '{"schema_name": "jaffle_shop", "generate_columns": true, "include_data_types": false}'
 ```
 
 2. The YAML for the source will be logged to the command line
@@ -208,6 +214,7 @@ schema.yml file.
 ### Arguments:
 * `model_names` (required): The model(s) you wish to generate YAML for.
 * `upstream_descriptions` (optional, default=False): Whether you want to include descriptions for identical column names from upstream models.
+* `include_data_types` (optional, default=True): Whether you want to add data types to your model column definitions.
 
 ### Usage:
 1. Create a model.
@@ -241,10 +248,13 @@ version: 2
 
 models:
   - name: customers
+    description: ""
     columns:
       - name: customer_id
+        data_type: integer
         description: ""
       - name: customer_name
+        data_type: text
         description: ""
 ```
 
@@ -255,7 +265,7 @@ This macro generates the SQL for a given model with all references pulled up int
 
 ### Arguments:
 * `model_name` (required): The model you wish to generate SQL with import CTEs for.
-* `leading_commas` (optional, default = false): Whether you want your commas to be leading (vs trailing).
+* `leading_commas` (optional, default=False): Whether you want your commas to be leading (vs trailing).
 
 ### Usage:
 1. Create a model with your original SQL query
diff --git a/integration_tests/macros/integer_type_value.sql b/integration_tests/macros/integer_type_value.sql
index f447110..207a43e 100644
--- a/integration_tests/macros/integer_type_value.sql
+++ b/integration_tests/macros/integer_type_value.sql
@@ -1,9 +1,9 @@
 {%- macro integer_type_value() -%}
 {%- if target.type == "snowflake" -%}
-NUMBER(38,0)
+number
 {%- elif target.type == "bigquery" -%}
-INT64
+int64
 {%- else -%}
-INTEGER
+integer
 {%- endif -%}
 {%- endmacro -%}
diff --git a/integration_tests/macros/text_type_value.sql b/integration_tests/macros/text_type_value.sql
index 929813f..514d4a8 100644
--- a/integration_tests/macros/text_type_value.sql
+++ b/integration_tests/macros/text_type_value.sql
@@ -1,11 +1,11 @@
-{%- macro text_type_value(text_length) -%}
-{%- if target.type == "redshift" -%}
-CHARACTER VARYING({{ text_length }})
+{%- macro text_type_value() -%}
+{%- if target.type == "redshift"-%}
+character varying
 {%- elif target.type == "snowflake" -%}
-CHARACTER VARYING(16777216)
+varchar
 {%- elif target.type == "bigquery" -%}
-STRING
+string
 {%- else -%}
-TEXT
+text
 {%- endif -%}
 {%- endmacro -%}
diff --git a/integration_tests/tests/test_generate_model_struct_yaml.sql b/integration_tests/tests/test_generate_model_struct_yaml.sql
index fc33bf4..148323b 100644
--- a/integration_tests/tests/test_generate_model_struct_yaml.sql
+++ b/integration_tests/tests/test_generate_model_struct_yaml.sql
@@ -10,7 +10,8 @@
 ) %}
 
 {% set actual_source_yaml = codegen.generate_model_yaml(
-    model_names=['model_struct']
+    model_names=['model_struct'],
+    include_data_types=False
   )
 %}
 
diff --git a/integration_tests/tests/test_generate_model_yaml.sql b/integration_tests/tests/test_generate_model_yaml.sql
index dbb9747..18e7a6a 100644
--- a/integration_tests/tests/test_generate_model_yaml.sql
+++ b/integration_tests/tests/test_generate_model_yaml.sql
@@ -11,9 +11,11 @@ models:
     description: ""
     columns:
       - name: col_a
+        data_type: {{ integer_type_value() }}
         description: ""
 
       - name: col_b
+        data_type: {{ text_type_value() }}
         description: ""
 
 {% endset %}
diff --git a/integration_tests/tests/test_generate_model_yaml_multiple_models.sql b/integration_tests/tests/test_generate_model_yaml_multiple_models.sql
index 843959f..c3dc203 100644
--- a/integration_tests/tests/test_generate_model_yaml_multiple_models.sql
+++ b/integration_tests/tests/test_generate_model_yaml_multiple_models.sql
@@ -1,5 +1,6 @@
 {% set actual_model_yaml = codegen.generate_model_yaml(
-    model_names=['data__a_relation','data__b_relation']
+    model_names=['data__a_relation','data__b_relation'],
+    include_data_types=False
   )
 %}
 
diff --git a/integration_tests/tests/test_generate_model_yaml_upstream_descriptions.sql b/integration_tests/tests/test_generate_model_yaml_upstream_descriptions.sql
index 71ecd89..73e6687 100644
--- a/integration_tests/tests/test_generate_model_yaml_upstream_descriptions.sql
+++ b/integration_tests/tests/test_generate_model_yaml_upstream_descriptions.sql
@@ -1,6 +1,7 @@
 {% set actual_model_yaml = codegen.generate_model_yaml(
     model_names=['child_model'],
-    upstream_descriptions=True
+    upstream_descriptions=True,
+    include_data_types=False
   )
 %}
 
diff --git a/integration_tests/tests/test_generate_source_all_args.sql b/integration_tests/tests/test_generate_source_all_args.sql
index f287aef..cf6703a 100644
--- a/integration_tests/tests/test_generate_source_all_args.sql
+++ b/integration_tests/tests/test_generate_source_all_args.sql
@@ -33,7 +33,7 @@ sources:
             data_type: {{ integer_type_value() }}
             description: ""
           - name: col_b
-            data_type: {{ text_type_value(1) }}
+            data_type: {{ text_type_value() }}
             description: ""
 
       - name: data__b_relation
@@ -43,26 +43,26 @@ sources:
             data_type: {{ integer_type_value() }}
             description: ""
           - name: col_b
-            data_type: {{ text_type_value(1) }}
+            data_type: {{ text_type_value() }}
             description: ""
 
       - name: data__campaign_analytics
         description: ""
         columns:
           - name: source
-            data_type: {{ text_type_value(8) }}
+            data_type: {{ text_type_value() }}
             description: ""
           - name: medium
-            data_type: {{ text_type_value(8) }}
+            data_type: {{ text_type_value() }}
             description: ""
           - name: source_medium
-            data_type: {{ text_type_value(2) }}
+            data_type: {{ text_type_value() }}
             description: ""
           - name: analytics
             data_type: {{ integer_type_value() }}
             description: ""
           - name: col_x
-            data_type: {{ text_type_value(1) }}
+            data_type: {{ text_type_value() }}
             description: ""
 
 {% endset %}
diff --git a/integration_tests/tests/test_generate_source_some_tables.sql b/integration_tests/tests/test_generate_source_some_tables.sql
index 525f712..1d7b43f 100644
--- a/integration_tests/tests/test_generate_source_some_tables.sql
+++ b/integration_tests/tests/test_generate_source_some_tables.sql
@@ -6,7 +6,8 @@
     database_name=target.database,
     table_names=['data__a_relation'],
     generate_columns=True,
-    include_descriptions=True
+    include_descriptions=True,
+    include_data_types=False
 ) %}
 
 
diff --git a/macros/generate_model_yaml.sql b/macros/generate_model_yaml.sql
index cdeab71..f226536 100644
--- a/macros/generate_model_yaml.sql
+++ b/macros/generate_model_yaml.sql
@@ -1,4 +1,4 @@
-{% macro generate_column_yaml(column, model_yaml, column_desc_dict, parent_column_name="") %}
+{% macro generate_column_yaml(column, model_yaml, column_desc_dict, include_data_types, parent_column_name="") %}
     {% if parent_column_name %}
         {% set column_name = parent_column_name ~ "." ~ column.name %}
     {% else %}
@@ -6,18 +6,21 @@
     {% endif %}
 
     {% do model_yaml.append('      - name: ' ~ column_name  | lower ) %}
+    {% if include_data_types %}
+        {% do model_yaml.append('        data_type: ' ~ codegen.data_type_format_model(column)) %}
+    {% endif %}
     {% do model_yaml.append('        description: "' ~ column_desc_dict.get(column.name | lower,'') ~ '"') %}
     {% do model_yaml.append('') %}
 
     {% if column.fields|length > 0 %}
         {% for child_column in column.fields %}
-            {% set model_yaml = codegen.generate_column_yaml(child_column, model_yaml, column_desc_dict, parent_column_name=column_name) %}
+            {% set model_yaml = codegen.generate_column_yaml(child_column, model_yaml, column_desc_dict, include_data_types, parent_column_name=column_name) %}
         {% endfor %}
     {% endif %}
     {% do return(model_yaml) %}
 {% endmacro %}
 
-{% macro generate_model_yaml(model_names=[], upstream_descriptions=False) %}
+{% macro generate_model_yaml(model_names=[], upstream_descriptions=False, include_data_types=True) %}
 
     {% set model_yaml=[] %}
 
@@ -38,7 +41,7 @@
             {% set column_desc_dict =  codegen.build_dict_column_descriptions(model) if upstream_descriptions else {} %}
 
             {% for column in columns %}
-                {% set model_yaml = codegen.generate_column_yaml(column, model_yaml, column_desc_dict) %}
+                {% set model_yaml = codegen.generate_column_yaml(column, model_yaml, column_desc_dict, include_data_types) %}
             {% endfor %}
         {% endfor %}
     {% endif %}
diff --git a/macros/generate_source.sql b/macros/generate_source.sql
index 5097655..31fd3e7 100644
--- a/macros/generate_source.sql
+++ b/macros/generate_source.sql
@@ -15,7 +15,7 @@
 
 
 ---
-{% macro generate_source(schema_name, database_name=target.database, generate_columns=False, include_descriptions=False, include_data_types=False, table_pattern='%', exclude='', name=schema_name, table_names=None, include_database=False, include_schema=False) %}
+{% macro generate_source(schema_name, database_name=target.database, generate_columns=False, include_descriptions=False, include_data_types=True, table_pattern='%', exclude='', name=schema_name, table_names=None, include_database=False, include_schema=False) %}
 
 {% set sources_yaml=[] %}
 {% do sources_yaml.append('version: 2') %}
@@ -62,7 +62,7 @@
         {% for column in columns %}
             {% do sources_yaml.append('          - name: ' ~ column.name | lower ) %}
             {% if include_data_types %}
-                {% do sources_yaml.append('            data_type: ' ~ (column.data_type | upper ) ) %}
+                {% do sources_yaml.append('            data_type: ' ~ codegen.data_type_format_source(column)) %}
             {% endif %}
             {% if include_descriptions %}
                 {% do sources_yaml.append('            description: ""' ) %}
diff --git a/macros/helpers/helpers.sql b/macros/helpers/helpers.sql
index fd28c87..557858e 100644
--- a/macros/helpers/helpers.sql
+++ b/macros/helpers/helpers.sql
@@ -57,4 +57,24 @@
         {% endfor %}
     {% endif %}
     {{ return(model_names) }}
-{% endmacro %}
\ No newline at end of file
+{% endmacro %}
+
+{% macro data_type_format_source(column) -%}
+  {{ return(adapter.dispatch('data_type_format_source', 'codegen')(column)) }}
+{%- endmacro %}
+
+{# format a column data type for a source #}
+{% macro default__data_type_format_source(column) %}
+    {% set formatted = codegen.format_column(column) %}
+    {{ return(formatted['data_type'] | lower) }}
+{% endmacro %}
+
+{% macro data_type_format_model(column) -%}
+  {{ return(adapter.dispatch('data_type_format_model', 'codegen')(column)) }}
+{%- endmacro %}
+
+{# format a column data type for a model #}
+{% macro default__data_type_format_model(column) %}
+    {% set formatted = codegen.format_column(column) %}
+    {{ return(formatted['data_type'] | lower) }}
+{% endmacro %}
diff --git a/macros/vendored/dbt_core/format_column.sql b/macros/vendored/dbt_core/format_column.sql
new file mode 100644
index 0000000..a7a6669
--- /dev/null
+++ b/macros/vendored/dbt_core/format_column.sql
@@ -0,0 +1,5 @@
+{% macro format_column(column) -%}
+  {% set data_type = column.dtype %}
+  {% set formatted = column.column.lower() ~ " " ~ data_type %}
+  {{ return({'name': column.name, 'data_type': data_type, 'formatted': formatted}) }}
+{%- endmacro -%}