diff --git a/README.md b/README.md
index 125cf6c..0c483b8 100644
--- a/README.md
+++ b/README.md
@@ -100,7 +100,7 @@ opt in.
 
 Environment variables set at the pipeline or stage level in `pipeline_fn` are
 handled automatically: variables identical across all regions in a group stay at
-the stage level, while region-specific variables are cascaded to the job level.
+their original level, while region-specific variables are cascaded to the job level.
 GoCD resolves precedence as job > stage > pipeline.
 
 ### Targeting a subset of regions
diff --git a/libs/pipedream.libsonnet b/libs/pipedream.libsonnet
index d9a3afb..17fbc5f 100644
--- a/libs/pipedream.libsonnet
+++ b/libs/pipedream.libsonnet
@@ -315,6 +315,25 @@ local generate_group_pipeline(pipedream_config, pipeline_fn, group, display_orde
     true
   );
 
+  // Returns the env vars whose value is identical across every region.
+  local common_env_vars(per_region_envs) =
+    local first = per_region_envs[regions[0]];
+    {
+      [k]: first[k]
+      for k in std.objectFields(first)
+      if std.length(std.filter(
+        function(r) std.objectHas(per_region_envs[r], k) && per_region_envs[r][k] == first[k],
+        regions
+      )) == std.length(regions)
+    };
+
+  // Pipeline-level env vars shared by all regions stay at pipeline level so they
+  // show up in GoCD's "Trigger with options" dialog and can be overridden per run.
+  local common_pipeline_env = common_env_vars({
+    [region]: get_pipeline_env_vars(region_pipelines[region])
+    for region in regions
+  });
+
   // Collect all unique stages across all regions in the group.
   // If a region doesn't define a stage that another region has,
   // it simply contributes no jobs to that stage.
@@ -339,8 +358,8 @@ local generate_group_pipeline(pipedream_config, pipeline_fn, group, display_orde
     if std.length(matching) > 0 then matching[0] else null;
 
   // Transforms a stage by aggregating jobs from all regions.
-  // Env vars identical across all regions are kept at stage level;
-  // region-specific env vars are cascaded down to the job level.
+  // Env vars identical across all regions are kept at stage level (unless already
+  // set at pipeline level); region-specific env vars are cascaded down to the job level.
   local transform_stage(stage) =
     local stage_name = get_stage_name(stage);
     local stage_props = get_stage_props(stage);
@@ -375,24 +394,23 @@ local generate_group_pipeline(pipedream_config, pipeline_fn, group, display_orde
       for region in regions
     };
 
-    // Env vars identical across ALL regions stay at stage level
-    local first_env = per_region_parent_envs[regions[0]];
+    // Env vars identical across ALL regions stay at stage level. Ones already at
+    // pipeline level with the same value are dropped so a trigger-time override isn't shadowed.
+    local stage_common_env = common_env_vars(per_region_parent_envs);
     local common_env = {
-      [k]: first_env[k]
-      for k in std.objectFields(first_env)
-      if std.length(std.filter(
-        function(r) std.objectHas(per_region_parent_envs[r], k) && per_region_parent_envs[r][k] == first_env[k],
-        regions
-      )) == std.length(regions)
+      [k]: stage_common_env[k]
+      for k in std.objectFields(stage_common_env)
+      if !(std.objectHas(common_pipeline_env, k) && common_pipeline_env[k] == stage_common_env[k])
     };
 
     local all_jobs = std.foldl(
       function(acc, region)
         local parent_env = per_region_parent_envs[region];
+        local inherited_env = common_pipeline_env + common_env;
         local region_specific_env = {
           [k]: parent_env[k]
           for k in std.objectFields(parent_env)
-          if !std.objectHas(common_env, k) || common_env[k] != parent_env[k]
+          if !std.objectHas(inherited_env, k) || inherited_env[k] != parent_env[k]
         };
         local p = region_pipelines[region];
         local region_stage = get_matching_stage(p, stage_name);
@@ -464,7 +482,7 @@ local generate_group_pipeline(pipedream_config, pipeline_fn, group, display_orde
     for stage in all_stages
   ];
 
-  // Strip pipeline and stage level environment variables
+  // Strip pipeline-level environment variables; shared ones are re-added below.
   local filtered_template = {
     [k]: template_pipeline[k]
     for k in std.objectFields(template_pipeline)
@@ -477,7 +495,7 @@ local generate_group_pipeline(pipedream_config, pipeline_fn, group, display_orde
   filtered_template {
     group: service_name,
     display_order: display_order,
-    environment_variables: {
+    environment_variables: common_pipeline_env {
       PIPEDREAM_GROUP_REGIONS: std.join(',', regions),
     },
     stages: prepend_stages + transformed_stages + [
diff --git a/test/testdata/fixtures/pipedream/env-vars-precedence.jsonnet b/test/testdata/fixtures/pipedream/env-vars-precedence.jsonnet
index c7b5a0c..77fd410 100644
--- a/test/testdata/fixtures/pipedream/env-vars-precedence.jsonnet
+++ b/test/testdata/fixtures/pipedream/env-vars-precedence.jsonnet
@@ -13,6 +13,7 @@ local pipeline_fn(region) = {
   // Pipeline-level env vars
   environment_variables: {
     PIPELINE_VAR: 'pipeline-' + region,  // Should cascade down to becoming a job level var
+    PIPELINE_SHARED_VAR: 'from-pipeline',  // Identical across regions, stays at pipeline level
     SHARED_VAR_JOB: 'from-pipeline',  // Should be overwritten by stage, then job
     SHARED_VAR_STAGE: 'from-pipeline',  // Overridden by stage
   },
diff --git a/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_output-files.golden b/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_output-files.golden
index 57c8d9d..99383ed 100644
--- a/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_output-files.golden
+++ b/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_output-files.golden
@@ -5,7 +5,11 @@
          "deploy-example-s4s2": {
             "display_order": 2,
             "environment_variables": {
-               "PIPEDREAM_GROUP_REGIONS": "s4s2"
+               "PIPEDREAM_GROUP_REGIONS": "s4s2",
+               "PIPELINE_SHARED_VAR": "from-pipeline",
+               "PIPELINE_VAR": "pipeline-s4s2",
+               "SHARED_VAR_JOB": "from-pipeline",
+               "SHARED_VAR_STAGE": "from-pipeline"
             },
             "group": "example",
             "materials": {
@@ -18,7 +22,6 @@
                {
                   "deploy": {
                      "environment_variables": {
-                        "PIPELINE_VAR": "pipeline-s4s2",
                         "SHARED_VAR_JOB": "from-stage",
                         "SHARED_VAR_STAGE": "from-stage",
                         "STAGE_VAR": "stage-s4s2"
@@ -64,7 +67,10 @@
          "deploy-example-st": {
             "display_order": 3,
             "environment_variables": {
-               "PIPEDREAM_GROUP_REGIONS": "customer-1,customer-2,customer-7"
+               "PIPEDREAM_GROUP_REGIONS": "customer-1,customer-2,customer-7",
+               "PIPELINE_SHARED_VAR": "from-pipeline",
+               "SHARED_VAR_JOB": "from-pipeline",
+               "SHARED_VAR_STAGE": "from-pipeline"
             },
             "group": "example",
             "materials": {
diff --git a/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_single-file.golden b/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_single-file.golden
index b513388..6058916 100644
--- a/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_single-file.golden
+++ b/test/testdata/goldens/pipedream/env-vars-precedence.jsonnet_single-file.golden
@@ -4,7 +4,11 @@
       "deploy-example-s4s2": {
          "display_order": 2,
          "environment_variables": {
-            "PIPEDREAM_GROUP_REGIONS": "s4s2"
+            "PIPEDREAM_GROUP_REGIONS": "s4s2",
+            "PIPELINE_SHARED_VAR": "from-pipeline",
+            "PIPELINE_VAR": "pipeline-s4s2",
+            "SHARED_VAR_JOB": "from-pipeline",
+            "SHARED_VAR_STAGE": "from-pipeline"
          },
          "group": "example",
          "materials": {
@@ -17,7 +21,6 @@
             {
                "deploy": {
                   "environment_variables": {
-                     "PIPELINE_VAR": "pipeline-s4s2",
                      "SHARED_VAR_JOB": "from-stage",
                      "SHARED_VAR_STAGE": "from-stage",
                      "STAGE_VAR": "stage-s4s2"
@@ -58,7 +61,10 @@
       "deploy-example-st": {
          "display_order": 3,
          "environment_variables": {
-            "PIPEDREAM_GROUP_REGIONS": "customer-1,customer-2,customer-7"
+            "PIPEDREAM_GROUP_REGIONS": "customer-1,customer-2,customer-7",
+            "PIPELINE_SHARED_VAR": "from-pipeline",
+            "SHARED_VAR_JOB": "from-pipeline",
+            "SHARED_VAR_STAGE": "from-pipeline"
          },
          "group": "example",
          "materials": {