diff --git a/.github/scripts/update-policyengine-package.sh b/.github/scripts/update-policyengine-package.sh
index 8a8a52c97..14f6ca9b6 100755
--- a/.github/scripts/update-policyengine-package.sh
+++ b/.github/scripts/update-policyengine-package.sh
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 #
 # Check PyPI for a newer policyengine.py package, update the simulation project
-# pin, sync country package pins to that policyengine.py bundle, and open one
+# pin, sync runtime package pins to that policyengine.py bundle, and open one
 # bundle-level PR.
 #
 # Usage:
@@ -39,7 +39,8 @@ create_pr_body_file() {
     echo
     echo "Update policyengine.py from ${CURRENT} to ${LATEST} in the simulation API runtime."
     echo
-    echo "This also syncs country package pins to the versions bundled by policyengine.py ${LATEST}:"
+    echo "This also syncs runtime package pins to the versions bundled by policyengine.py ${LATEST}:"
+    echo "- policyengine-core: ${BUNDLED_CORE_VERSION:-resolved from bundle during update}"
     echo "- policyengine-us: ${BUNDLED_US_VERSION:-resolved from bundle during update}"
     echo "- policyengine-uk: ${BUNDLED_UK_VERSION:-resolved from bundle during update}"
     echo
@@ -160,26 +161,29 @@ BUNDLE_OUTPUT=$(
 )
 BUNDLED_US_VERSION=$(printf '%s\n' "$BUNDLE_OUTPUT" | awk -F= '$1 == "us_version" {print $2}')
 BUNDLED_UK_VERSION=$(printf '%s\n' "$BUNDLE_OUTPUT" | awk -F= '$1 == "uk_version" {print $2}')
+BUNDLED_CORE_VERSION=$(printf '%s\n' "$BUNDLE_OUTPUT" | awk -F= '$1 == "policyengine_core_version" {print $2}')
 
-if [[ -z "$BUNDLED_US_VERSION" || -z "$BUNDLED_UK_VERSION" ]]; then
-  echo "ERROR: Could not resolve bundled country package versions." >&2
+if [[ -z "$BUNDLED_CORE_VERSION" || -z "$BUNDLED_US_VERSION" || -z "$BUNDLED_UK_VERSION" ]]; then
+  echo "ERROR: Could not resolve bundled runtime package versions." >&2
   echo "$BUNDLE_OUTPUT" >&2
   exit 1
 fi
 
-echo "Bundled country pins:"
+echo "Bundled runtime pins:"
+echo "  policyengine-core==${BUNDLED_CORE_VERSION}"
 echo "  policyengine-us==${BUNDLED_US_VERSION}"
 echo "  policyengine-uk==${BUNDLED_UK_VERSION}"
 
-python3 - "$PYPROJECT" "$BUNDLED_US_VERSION" "$BUNDLED_UK_VERSION" <<'PY'
+python3 - "$PYPROJECT" "$BUNDLED_CORE_VERSION" "$BUNDLED_US_VERSION" "$BUNDLED_UK_VERSION" <<'PY'
 import re
 import sys
 from pathlib import Path
 
-pyproject_path, us_version, uk_version = sys.argv[1:]
+pyproject_path, core_version, us_version, uk_version = sys.argv[1:]
 pyproject = Path(pyproject_path)
 text = pyproject.read_text(encoding="utf-8")
 pins = {
+    "policyengine-core": core_version,
     "policyengine-us": us_version,
     "policyengine-uk": uk_version,
 }
diff --git a/projects/policyengine-api-simulation/fixtures/test_policyengine_package_update_scripts.py b/projects/policyengine-api-simulation/fixtures/test_policyengine_package_update_scripts.py
index 77dd580c9..082e27f1f 100644
--- a/projects/policyengine-api-simulation/fixtures/test_policyengine_package_update_scripts.py
+++ b/projects/policyengine-api-simulation/fixtures/test_policyengine_package_update_scripts.py
@@ -22,7 +22,7 @@ def fake_repo(tmp_path: Path) -> Path:
         "\n".join(
             [
                 "[project]",
-                'dependencies = ["policyengine==4.0.0", "policyengine-us==1.0.0", "policyengine-uk==2.0.0"]',
+                'dependencies = ["policyengine==4.0.0", "policyengine-core==0.0.0", "policyengine-us==1.0.0", "policyengine-uk==2.0.0"]',
             ]
         ),
         encoding="utf-8",
@@ -35,6 +35,10 @@ def fake_repo(tmp_path: Path) -> Path:
                 'version = "4.0.0"',
                 "",
                 "[[package]]",
+                'name = "policyengine-core"',
+                'version = "0.0.0"',
+                "",
+                "[[package]]",
                 'name = "policyengine-us"',
                 'version = "1.0.0"',
                 "",
@@ -124,6 +128,7 @@ def install_fake_uv(
     fake_bin: Path,
     *,
     log: Path,
+    bundled_core_version: str = "999.999.999",
     bundled_us_version: str = "1.1.0",
     bundled_uk_version: str = "2.1.0",
 ) -> None:
@@ -135,7 +140,7 @@ def install_fake_uv(
 
 if [[ "$1" == "run" && "$2" == "python" && "$3" == "-m" && "$4" == "src.modal.utils.extract_bundle_versions" ]]; then
   echo "policyengine_version=4.1.0"
-  echo "policyengine_core_version=3.26.1"
+  echo "policyengine_core_version={bundled_core_version}"
   echo "us_version={bundled_us_version}"
   echo "us_data_version=1.10.0"
   echo "uk_version={bundled_uk_version}"
diff --git a/projects/policyengine-api-simulation/pyproject.toml b/projects/policyengine-api-simulation/pyproject.toml
index cd6f7b041..f1a9a6996 100644
--- a/projects/policyengine-api-simulation/pyproject.toml
+++ b/projects/policyengine-api-simulation/pyproject.toml
@@ -16,10 +16,10 @@ dependencies = [
     "pydantic-settings (>=2.7.1,<3.0.0)",
     "opentelemetry-instrumentation-fastapi (>=0.51b0,<0.52)",
     "policyengine-fastapi",
-    "policyengine==4.18.3",
-    "policyengine-core==3.27.1",
+    "policyengine==4.18.5",
+    "policyengine-core==3.28.0",
     "policyengine-uk==2.89.2",
-    "policyengine-us==1.729.0",
+    "policyengine-us==1.745.0",
     "tables>=3.10.2",
     "modal>=0.73.0",
     "logfire>=3.0.0",
diff --git a/projects/policyengine-api-simulation/tests/test_policyengine_package_update_scripts.py b/projects/policyengine-api-simulation/tests/test_policyengine_package_update_scripts.py
index 6849c19f6..ba88d2241 100644
--- a/projects/policyengine-api-simulation/tests/test_policyengine_package_update_scripts.py
+++ b/projects/policyengine-api-simulation/tests/test_policyengine_package_update_scripts.py
@@ -128,7 +128,7 @@ def test_update_policyengine_package_opens_pr_for_existing_branch_without_open_p
     assert "--head auto/update-policyengine-4.1.0" in gh_calls
 
 
-def test_update_policyengine_package_updates_py_and_bundled_country_pins(
+def test_update_policyengine_package_updates_py_and_bundled_runtime_pins(
     fake_bin: Path, fake_repo: Path, tmp_path: Path
 ) -> None:
     git_log = tmp_path / "git.log"
@@ -149,6 +149,7 @@ def test_update_policyengine_package_updates_py_and_bundled_country_pins(
         encoding="utf-8"
     )
     assert "policyengine==4.1.0" in pyproject_text
+    assert "policyengine-core==999.999.999" in pyproject_text
     assert "policyengine-us==1.1.0" in pyproject_text
     assert "policyengine-uk==2.1.0" in pyproject_text
     uv_calls = uv_log.read_text(encoding="utf-8")
diff --git a/projects/policyengine-api-simulation/uv.lock b/projects/policyengine-api-simulation/uv.lock
index 38f4848cd..2cf1d0aac 100644
--- a/projects/policyengine-api-simulation/uv.lock
+++ b/projects/policyengine-api-simulation/uv.lock
@@ -1635,7 +1635,7 @@ name = "pexpect"
 version = "4.9.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "ptyprocess", marker = "sys_platform != 'emscripten' and sys_platform != 'win32'" },
+    { name = "ptyprocess" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/42/92/cc564bf6381ff43ce1f4d06852fc19a2f11d180f23dc32d9588bee2f149d/pexpect-4.9.0.tar.gz", hash = "sha256:ee7d41123f3c9911050ea2c2dac107568dc43b2d3b0c7557a33212c398ead30f", size = 166450, upload-time = "2023-11-25T09:07:26.339Z" }
 wheels = [
@@ -1675,7 +1675,7 @@ wheels = [
 
 [[package]]
 name = "policyengine"
-version = "4.18.3"
+version = "4.18.5"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "diskcache" },
@@ -1689,14 +1689,14 @@ dependencies = [
     { name = "pydantic" },
     { name = "requests" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/de/13/0dd4f39d7ec5d14add10c08e4d61aad296831802edae526e1907fc023aec/policyengine-4.18.3.tar.gz", hash = "sha256:ed95cfea02770e62bc0945a9e88bcbc96c94bf1fc717162c194b33948564a089", size = 697659, upload-time = "2026-06-25T19:05:19.468Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/21/2c/5e600a757fd03e227b99009067c6e4e05c97c9d05cc1e28410f7a3fef9b5/policyengine-4.18.5.tar.gz", hash = "sha256:a4d484964856debd1ce18fcf71ac9957e8a4cf897a2bb2652953bd191695b8c7", size = 697884, upload-time = "2026-06-27T06:44:22.182Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/7f/b9/b3651013363f71c90795c7fd11ae7eed2b9acb2bafeb743260b972f2d58b/policyengine-4.18.3-py3-none-any.whl", hash = "sha256:fe2adbb576c08acb874ad98b5b03b8c41c38f654cd41ad6ada14a32427774aa0", size = 211031, upload-time = "2026-06-25T19:05:17.906Z" },
+    { url = "https://files.pythonhosted.org/packages/d7/b7/d2abead0bb24e497950b2e2cbd847c544c25d97dd4ad6c641084e6f754ed/policyengine-4.18.5-py3-none-any.whl", hash = "sha256:960469cec0ad47d85e64151c3c9cf0db6b38624b2bae66cedbd993ae32ee7a55", size = 211057, upload-time = "2026-06-27T06:44:20.607Z" },
 ]
 
 [[package]]
 name = "policyengine-core"
-version = "3.27.1"
+version = "3.28.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "dpath" },
@@ -1716,9 +1716,9 @@ dependencies = [
     { name = "standard-imghdr" },
     { name = "wheel" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/15/28/cbc23d0c61d431cbfdbaea3f7a71b2230187ab2e57f1430a551598b39515/policyengine_core-3.27.1.tar.gz", hash = "sha256:21471e3f6e95b8d5c00babcb5a5d363fdc1cd4b02c338e5eb4c9da18e08b6a10", size = 484853, upload-time = "2026-06-11T18:18:36.753Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/69/bf/d870af03abe76a64249fe9e95d7561c99c0484af1d3f3ae3773caa1c57d8/policyengine_core-3.28.0.tar.gz", hash = "sha256:3ae894577d8c40cb6c6d0f7d1df8ccdce2ee46aecbe52de0604e0af7ed454ecb", size = 484615, upload-time = "2026-06-26T13:38:51.09Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/30/81/098994e62401e9ce0d799e3f01329ba4a8792599d17ae0ef67fff1ddd3ff/policyengine_core-3.27.1-py3-none-any.whl", hash = "sha256:dac7928b502baa56fd22956f089689faa4d7e04a21aab7f1f29b34961d684ef8", size = 238480, upload-time = "2026-06-11T18:18:35.203Z" },
+    { url = "https://files.pythonhosted.org/packages/49/b6/efec8f49cc926cd8aa4f6767ae56d1d29e31fc42fc1efebed611cb8499c3/policyengine_core-3.28.0-py3-none-any.whl", hash = "sha256:069b83f76f636c138975ca85270500e47b81f191bc00da47090b237500eeabc0", size = 238479, upload-time = "2026-06-26T13:38:49.705Z" },
 ]
 
 [[package]]
@@ -1798,11 +1798,11 @@ requires-dist = [
     { name = "openapi-python-client", marker = "extra == 'build'", specifier = ">=0.21.6" },
     { name = "opentelemetry-instrumentation-fastapi", specifier = ">=0.51b0,<0.52" },
     { name = "opentelemetry-instrumentation-sqlalchemy", specifier = ">=0.51b0,<0.52" },
-    { name = "policyengine", specifier = "==4.18.3" },
-    { name = "policyengine-core", specifier = "==3.27.1" },
+    { name = "policyengine", specifier = "==4.18.5" },
+    { name = "policyengine-core", specifier = "==3.28.0" },
     { name = "policyengine-fastapi", editable = "../../libs/policyengine-fastapi" },
     { name = "policyengine-uk", specifier = "==2.89.2" },
-    { name = "policyengine-us", specifier = "==1.729.0" },
+    { name = "policyengine-us", specifier = "==1.745.0" },
     { name = "pydantic-settings", specifier = ">=2.7.1,<3.0.0" },
     { name = "pyright", marker = "extra == 'build'", specifier = ">=1.1.401" },
     { name = "pytest", marker = "extra == 'test'", specifier = ">=8.3.4" },
@@ -1829,7 +1829,7 @@ wheels = [
 
 [[package]]
 name = "policyengine-us"
-version = "1.729.0"
+version = "1.745.0"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
     { name = "microdf-python" },
@@ -1839,9 +1839,9 @@ dependencies = [
     { name = "tables" },
     { name = "tqdm" },
 ]
-sdist = { url = "https://files.pythonhosted.org/packages/69/cb/b2efba2094a708cd71890d98d72b99394fabc5894a4cceec14381e03fa35/policyengine_us-1.729.0.tar.gz", hash = "sha256:ac05c4d621c7f848b0806effc14e913160d5d47d777eadced6bc18edf392d75c", size = 10373862, upload-time = "2026-06-14T18:05:25.747Z" }
+sdist = { url = "https://files.pythonhosted.org/packages/3f/87/bb5e15d5e63208d6451393818f35a1824f8808e44d9a491ade601e59e20c/policyengine_us-1.745.0.tar.gz", hash = "sha256:7c93f8e7c46ef85fb50871f44bceed7da697400484fe79318db7b2d981c855c0", size = 10561674, upload-time = "2026-06-25T04:18:52.45Z" }
 wheels = [
-    { url = "https://files.pythonhosted.org/packages/b9/7d/778f92ae94997b00c3c9ac34b345f6c9333435f905670ee4eeb2f5e19809/policyengine_us-1.729.0-py3-none-any.whl", hash = "sha256:8d21d3f7c0e82a9415edffe8ea53939330a63d9c8f6bd334299bddb697cf2c00", size = 11905076, upload-time = "2026-06-14T18:05:21.806Z" },
+    { url = "https://files.pythonhosted.org/packages/49/36/ef50de1108cd0e0b89a7820ac3262bda7701d5ac6d998c27e570e63b7b82/policyengine_us-1.745.0-py3-none-any.whl", hash = "sha256:2af30b694b681adca7c2e2bd695bbeb41c03769d9ae908f82f671f8502ce32d9", size = 12300884, upload-time = "2026-06-25T04:18:49.056Z" },
 ]
 
 [[package]]