diff --git a/README.md b/README.md
index 94c8a50..f3c6b63 100644
--- a/README.md
+++ b/README.md
@@ -37,3 +37,30 @@ to set the version everywhere that it needs to be.
 
 Once that's done, the workflow will start, and you should see a release appear
 in the next few minutes.
+
+## Migration Procedure
+
+Because this application relies on a structured relational database schema,
+changes to the schema must be handled with care to avoid destroying users' data.
+Specifically, when changes are made to the schema, a *migration* must be defined
+which provides instructions for Perfin to safely apply changes to an old schema.
+
+The database schema is versioned using whole-number versions (1, 2, 3, ...), and
+a migration is defined for each transition from version to version, such that
+any older version can be incrementally upgraded, step by step, to the latest
+schema version.
+
+Perfin only supports the latest schema version, as defined by `JdbcDataSourceFactory.SCHEMA_VERSION`.
+When the app loads a profile, it'll check that profile's schema version by
+reading a `.jdbc-schema-version.txt` file in the profile's main directory. If
+the profile's schema version is **less than** the current, Perfin will
+ask the user if they want to upgrade. If the profile's schema version is
+**greater than** the current, Perfin will tell the user that it can't load a
+schema from a newer version, and will prompt the user to upgrade.
+
+### Writing a Migration
+
+1. Write your migration. This can be plain SQL (placed in `resources/sql/migration`), or Java code.
+2. Add your migration to `com.andrewlalis.perfin.data.impl.migration.Migrations#getMigrations()`.
+3. Increment the schema version defined in `JdbcDataSourceFactory`.
+4. Test the migration yourself on a profile with data.
diff --git a/src/main/java/com/andrewlalis/perfin/control/CategoriesViewController.java b/src/main/java/com/andrewlalis/perfin/control/CategoriesViewController.java
index 9697e76..a006b25 100644
--- a/src/main/java/com/andrewlalis/perfin/control/CategoriesViewController.java
+++ b/src/main/java/com/andrewlalis/perfin/control/CategoriesViewController.java
@@ -2,6 +2,9 @@ package com.andrewlalis.perfin.control;
 
 import com.andrewlalis.javafx_scene_router.RouteSelectionListener;
 import com.andrewlalis.perfin.data.TransactionCategoryRepository;
+import com.andrewlalis.perfin.data.impl.JdbcDataSource;
+import com.andrewlalis.perfin.data.impl.JdbcDataSourceFactory;
+import com.andrewlalis.perfin.data.util.DbUtil;
 import com.andrewlalis.perfin.model.Profile;
 import com.andrewlalis.perfin.view.BindingUtil;
 import com.andrewlalis.perfin.view.component.CategoryTile;
@@ -11,6 +14,9 @@ import javafx.collections.ObservableList;
 import javafx.fxml.FXML;
 import javafx.scene.layout.VBox;
 
+import java.io.IOException;
+import java.io.UncheckedIOException;
+
 import static com.andrewlalis.perfin.PerfinApp.router;
 
 public class CategoriesViewController implements RouteSelectionListener {
@@ -36,4 +42,22 @@ public class CategoriesViewController implements RouteSelectionListener {
                 TransactionCategoryRepository::findTree
         ).thenAccept(nodes -> Platform.runLater(() -> categoryTreeNodes.setAll(nodes)));
     }
+
+    @FXML public void addDefaultCategories() {
+        boolean confirm = Popups.confirm(categoriesVBox, "Are you sure you want to add all of Perfin's default categories to your profile? This might interfere with existing categories of the same name.");
+        if (!confirm) return;
+        JdbcDataSource ds = (JdbcDataSource) Profile.getCurrent().dataSource();
+        try (var conn = ds.getConnection()) {
+            DbUtil.doTransaction(conn, () -> {
+                try {
+                    new JdbcDataSourceFactory().insertDefaultCategories(conn);
+                } catch (IOException e) {
+                    throw new UncheckedIOException(e);
+                }
+            });
+            refreshCategories();
+        } catch (Exception e) {
+            Popups.error(categoriesVBox, e);
+        }
+    }
 }
diff --git a/src/main/java/com/andrewlalis/perfin/data/impl/JdbcDataSourceFactory.java b/src/main/java/com/andrewlalis/perfin/data/impl/JdbcDataSourceFactory.java
index d5320f4..bdad590 100644
--- a/src/main/java/com/andrewlalis/perfin/data/impl/JdbcDataSourceFactory.java
+++ b/src/main/java/com/andrewlalis/perfin/data/impl/JdbcDataSourceFactory.java
@@ -100,7 +100,18 @@ public class JdbcDataSourceFactory implements DataSourceFactory {
         }
     }
 
-    private void insertDefaultData(Connection conn) throws IOException, SQLException {
+    /**
+     * Inserts all default data into the database, using static content found in
+     * various locations on the classpath.
+     * @param conn The connection to use to insert data.
+     * @throws IOException If resources couldn't be read.
+     * @throws SQLException If SQL fails.
+     */
+    public void insertDefaultData(Connection conn) throws IOException, SQLException {
+        insertDefaultCategories(conn);
+    }
+
+    public void insertDefaultCategories(Connection conn) throws IOException, SQLException {
         try (
                 var categoriesIn = JdbcDataSourceFactory.class.getResourceAsStream("/sql/data/default-categories.json");
                 var stmt = conn.prepareStatement(
diff --git a/src/main/resources/categories-view.fxml b/src/main/resources/categories-view.fxml
index 9b0641c..c34b38f 100644
--- a/src/main/resources/categories-view.fxml
+++ b/src/main/resources/categories-view.fxml
@@ -24,6 +24,7 @@
             </StyledText>
             <HBox styleClass="std-padding, std-spacing" VBox.vgrow="NEVER">
                 <Button text="Add Category" onAction="#addCategory"/>
+                <Button text="Add Default Categories" onAction="#addDefaultCategories"/>
             </HBox>
             <ScrollPane styleClass="tile-container-scroll" VBox.vgrow="ALWAYS">
                 <VBox fx:id="categoriesVBox" styleClass="tile-container"/>