diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e739461d..fde2ce6e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -32,7 +32,6 @@ jobs:
     with:
       envs: |
         - linux: py310
-        - linux: py310-numpy123
         - linux: py310-numpy125
         - linux: py311
           pytest-results-summary: true
@@ -44,25 +43,3 @@ jobs:
           pytest-results-summary: true
         - linux: py312
         - linux: py3-dev
-  environment:
-    runs-on: ubuntu-latest
-    steps:
-      - id: data_path
-        run: echo "path=${{ env.DATA_PATH }}" >> $GITHUB_OUTPUT
-    outputs:
-      data_path: ${{ steps.data_path.outputs.path }}
-  crds_contexts:
-    uses: ./.github/workflows/contexts.yml
-  test_downstream:
-    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@924441154cf3053034c6513d5e06c69d262fb9a6  # v1.13.0
-    needs: [ environment, crds_contexts ]
-    with:
-      setenv: |
-        CRDS_PATH: ${{ needs.environment.outputs.data_path }}/crds
-        CRDS_SERVER_URL: https://jwst-crds.stsci.edu
-        CRDS_CLIENT_RETRY_COUNT: 3
-        CRDS_CLIENT_RETRY_DELAY_SECONDS: 20
-      cache-path: ${{ needs.environment.outputs.data_path }}/crds
-      cache-key: crds-${{ needs.crds_contexts.outputs.jwst }}
-      envs: |
-        - linux: py311-test-jwst-cov-xdist
diff --git a/.github/workflows/downstream.yml b/.github/workflows/downstream.yml
new file mode 100644
index 00000000..f15f1ec1
--- /dev/null
+++ b/.github/workflows/downstream.yml
@@ -0,0 +1,89 @@
+name: Downstream
+
+on:
+  workflow_dispatch:
+  schedule:
+    # Weekly Monday 9AM build
+    # * is a special character in YAML so you have to quote this string
+    - cron: '0 9 * * 1'
+  pull_request:
+    # We also want this workflow triggered if the `Downstream CI` label is
+    # added or present when PR is updated
+    types:
+      - synchronize
+      - labeled
+  push:
+    tags:
+      - '*'
+
+env:
+  DATA_PATH: /tmp/data
+
+# Only cancel in-progress jobs or runs for the current workflow
+#   This cancels the already triggered workflows for a specific PR without canceling
+#   other instances of this workflow (other PRs, scheduled triggers, etc) when something
+#   within that PR re-triggers this CI
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  environment:
+    runs-on: ubuntu-latest
+    steps:
+      - id: data_path
+        run: echo "path=${{ env.DATA_PATH }}" >> $GITHUB_OUTPUT
+    outputs:
+      data_path: ${{ steps.data_path.outputs.path }}
+
+  crds_contexts:
+    uses: ./.github/workflows/contexts.yml
+
+  jwst:
+    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@924441154cf3053034c6513d5e06c69d262fb9a6  # v1.13.0
+    needs: [ environment, crds_contexts ]
+    with:
+      setenv: |
+        CRDS_PATH: ${{ needs.environment.outputs.data_path }}/crds
+        CRDS_SERVER_URL: https://jwst-crds.stsci.edu
+        CRDS_CLIENT_RETRY_COUNT: 3
+        CRDS_CLIENT_RETRY_DELAY_SECONDS: 20
+      cache-path: ${{ needs.environment.outputs.data_path }}/crds
+      cache-key: crds-${{ needs.crds_contexts.outputs.jwst }}
+      envs: |
+        - linux: py311-test-jwst-cov-xdist
+
+  romancal:
+    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@924441154cf3053034c6513d5e06c69d262fb9a6  # v1.13.0
+    needs: [ environment, crds_contexts ]
+    with:
+      setenv: |
+        CRDS_PATH: ${{ needs.environment.outputs.data_path }}/crds
+        CRDS_SERVER_URL: https://roman-crds.stsci.edu
+        CRDS_CLIENT_RETRY_COUNT: 3
+        CRDS_CLIENT_RETRY_DELAY_SECONDS: 20
+      cache-path: ${{ needs.environment.outputs.data_path }}/crds
+      cache-key: crds-${{ needs.crds_contexts.outputs.jwst }}
+      envs: |
+        - linux: py311-test-romancal-cov-xdist
+
+  astropy:
+    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@924441154cf3053034c6513d5e06c69d262fb9a6  # v1.13.0
+    if: (github.repository == 'spacetelescope/gwcs' && (github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'workflow_dispatch' || contains(github.event.pull_request.labels.*.name, 'Downstream CI')))
+    with:
+      submodules: false
+      # Any env name which does not start with `pyXY` will use this Python version.
+      default_python: '3.11'
+      envs: |
+        - linux: specutils
+
+  third-party:
+    uses: OpenAstronomy/github-actions-workflows/.github/workflows/tox.yml@924441154cf3053034c6513d5e06c69d262fb9a6  # v1.13.0
+    if: (github.repository == 'spacetelescope/gwcs' && (github.event_name == 'schedule' || github.event_name == 'push' || github.event_name == 'workflow_dispatch' || contains(github.event.pull_request.labels.*.name, 'Downstream CI')))
+    with:
+      submodules: false
+      # Any env name which does not start with `pyXY` will use this Python version.
+      default_python: '3.11'
+      envs: |
+        - linux: ndcube
+        - linux: dkist
\ No newline at end of file
diff --git a/tox.ini b/tox.ini
index 59e42fef..f5e2ae74 100644
--- a/tox.ini
+++ b/tox.ini
@@ -100,3 +100,48 @@ deps =
     build
 commands =
     python -m build .
+
+[testenv:specutils]
+change_dir = {env_tmp_dir}
+allowlist_externals =
+    git
+    bash
+extras =
+commands_pre =
+    bash -c "pip freeze -q | grep 'gwcs @' > {env_tmp_dir}/requirements.txt"
+    git clone https://github.com/astropy/specutils.git
+    pip install -e specutils[test]
+    pip install -r {env_tmp_dir}/requirements.txt
+    pip list
+commands =
+    pytest specutils
+
+[testenv:dkist]
+change_dir = {env_tmp_dir}
+allowlist_externals =
+    git
+    bash
+extras =
+commands_pre =
+    bash -c "pip freeze -q | grep 'gwcs @' > {env_tmp_dir}/requirements.txt"
+    git clone https://github.com/DKISTDC/dkist.git
+    pip install -e dkist[tests]
+    pip install -r {env_tmp_dir}/requirements.txt
+    pip list
+commands =
+    pytest dkist --benchmark-skip
+
+[testenv:ndcube]
+change_dir = {env_tmp_dir}
+allowlist_externals =
+    git
+    bash
+extras =
+commands_pre =
+    bash -c "pip freeze -q | grep 'gwcs @' > {env_tmp_dir}/requirements.txt"
+    git clone https://github.com/sunpy/ndcube.git
+    pip install -e ndcube[all,tests]
+    pip install -r {env_tmp_dir}/requirements.txt
+    pip freeze
+commands =
+    pytest ndcube