MaxGhenis · Sep 28, 2026 · Sep 28, 2026 · Sep 28, 2026 · Sep 28, 2026
diff --git a/changelog.d/us-cd-crosswalk-north-carolina-117th.fixed.md b/changelog.d/us-cd-crosswalk-north-carolina-117th.fixed.md
@@ -0,0 +1 @@
+Build the packaged 117th->119th congressional-district crosswalk from the CD plan registry, so North Carolina's SOI districts map through its 2019 plan (the 117th Congress's) instead of the 2016 plan in the 2020 BAF layer. Only North Carolina's rows change; the crosswalk sha256 is now a347303f.
diff --git a/docs/evidence/spec-engine/us-f0-coverage.json b/docs/evidence/spec-engine/us-f0-coverage.json
@@ -1887,7 +1887,7 @@
             "alpha",
             "zeta"
           ],
-          "sha256": "b7a336af7cb300905d09ad9a33aa1a624f878c2471352d4e252fa69db55aee17"
+          "sha256": "3db095ce2d1ef89028d3862f0edc827d704f099c5b3323f9b115642a3c27e007"
         },
         "failures": [],
         "observed": {
@@ -1911,7 +1911,7 @@
             "alpha",
             "zeta"
           ],
-          "sha256": "b7a336af7cb300905d09ad9a33aa1a624f878c2471352d4e252fa69db55aee17"
+          "sha256": "3db095ce2d1ef89028d3862f0edc827d704f099c5b3323f9b115642a3c27e007"
         },
         "status": "covered"
       },
@@ -2045,7 +2045,7 @@
             "congressional_district_vintage_crosswalk",
             "puma_ladder"
           ],
-          "sha256": "f49425ca8734ac559c73cf44f6458d86d3162a48956b98a27e6e758959361585",
+          "sha256": "44e7f5f6cd7ceeef85d532c3d46306d03de4f4ee811376e6d29920742746b65c",
           "target_vintage": "119th_congress"
         },
         "failures": [],
@@ -2054,7 +2054,7 @@
             "congressional_district_vintage_crosswalk",
             "puma_ladder"
           ],
-          "sha256": "f49425ca8734ac559c73cf44f6458d86d3162a48956b98a27e6e758959361585",
+          "sha256": "44e7f5f6cd7ceeef85d532c3d46306d03de4f4ee811376e6d29920742746b65c",
           "target_vintage": "119th_congress"
         },
         "status": "covered"
@@ -2599,7 +2599,7 @@
       "country": "us",
       "schema_id": "country_spec",
       "schema_version": 1,
-      "spec_sha256": "1cf1f44d9a11458f59ea7d75dce68303816cab3e66668a6c6f6ecfe62d56f8dc"
+      "spec_sha256": "ffbb93ed5ae22a95536ae475d6912a42628568609b442360dc1cd3bcf26772cd"
     }
   },
   "report_schema_version": 3,
@@ -2609,7 +2609,7 @@
     "country": "us",
     "schema_id": "country_spec",
     "schema_version": 1,
-    "spec_sha256": "1cf1f44d9a11458f59ea7d75dce68303816cab3e66668a6c6f6ecfe62d56f8dc"
+    "spec_sha256": "ffbb93ed5ae22a95536ae475d6912a42628568609b442360dc1cd3bcf26772cd"
   },
   "status": "pass"
 }
diff --git a/packages/microcosm-build/src/microcosm/build/spec_engine/inventory_coverage.py b/packages/microcosm-build/src/microcosm/build/spec_engine/inventory_coverage.py
@@ -350,10 +350,10 @@
     "acs_person_predictors": "878c788a6f037d7aca12b3586ea034eff04f3034ffa11935a736493042551f25",
     "authority": "9d4a9672a0f03039b1fe874b9fe21ed575be0d29f14afc396d03cdf5c809bdd2",
     "early_families": "4aa9f736fd76e83955477ad1667e58f48f264783f05bdc7f0102cd32d61323bd",
-    "full_checkpoint": "b7a336af7cb300905d09ad9a33aa1a624f878c2471352d4e252fa69db55aee17",
+    "full_checkpoint": "3db095ce2d1ef89028d3862f0edc827d704f099c5b3323f9b115642a3c27e007",
     "gap_fill_schedule": "1c31f9868f7884347cc19cf1ff65da43f950b9114941a715bab168246db414a7",
     "graph_nodes": "40cd51ffdfe2e9d9d08d48c08e8ded9de1e4b134783bab05c4abc6ad5c72ca1e",
-    "geography_assignment": "f49425ca8734ac559c73cf44f6458d86d3162a48956b98a27e6e758959361585",
+    "geography_assignment": "44e7f5f6cd7ceeef85d532c3d46306d03de4f4ee811376e6d29920742746b65c",
     "late_families": "d91f9ff0eb52f43e7b6eed3d5c58c37abe1620c3a11021da15dae9c10e16d382",
     "late_resource_semantics": "cc34ba11288d01145fc2dc1a669df3f7c4ef2019d73afb02dd8eeee852b16d20",
     "late_schedule": "e59c019d3d454eac99ac0ac209b6c5b6faaf9bdfcaeee18c36a25be19bf7da2f",

diff --git a/packages/microcosm-build/src/microcosm/build/us/spec/sources.yaml b/packages/microcosm-build/src/microcosm/build/us/spec/sources.yaml
@@ -86,8 +86,8 @@ sources:
     value: 2020_puma
 - id: us_congressional_district_vintage_crosswalk_117_to_119
   role: congressional_district_vintage_crosswalk
-  sha256: c7cb040b1f57ca2ea2adcbfe60cc2b250ca23acbc4b640cd421e766fa54c1aec
-  byte_size: 77935
+  sha256: a347303fff3fea145f758488c43cb94355df5a8cb5e512552b2ee3791d2aa233
+  byte_size: 78202
   loader: kernel:load_congressional_district_vintage_crosswalk
   vintages:
   - vintage:cd_117

diff --git a/packages/microcosm-build/src/microcosm/build/us_runtime/congressional_district_vintage.py b/packages/microcosm-build/src/microcosm/build/us_runtime/congressional_district_vintage.py
@@ -100,9 +100,10 @@ def load_default_congressional_district_vintage_crosswalk() -> pd.DataFrame:
     """Load the packaged Census-built default 117th->119th CD crosswalk.
 
     This is the canonical, versioned crosswalk built by
-    ``tools/build_us_congressional_district_vintage_crosswalk.py`` from Census
-    Block Assignment Files, the 119th BEF, and 2020 P.L. 94-171 block
-    populations. Builds may still pass an explicit crosswalk path to override it.
+    ``tools/build_us_congressional_district_vintage_crosswalk.py`` from the
+    block -> congressional-district plan registry (117th and 119th plans on
+    2020 blocks, weighted by 2020 P.L. 94-171 block populations). Builds may
+    still pass an explicit crosswalk path to override it.
     """
 
     return load_congressional_district_vintage_crosswalk(

diff --git a/...icrocosm-build/src/microcosm/build/us_runtime/congressional_district_vintage_crosswalk.py b/...icrocosm-build/src/microcosm/build/us_runtime/congressional_district_vintage_crosswalk.py
@@ -1,27 +1,30 @@
-"""Build the 117th->119th congressional-district vintage crosswalk from Census.
+"""Build the 117th->119th congressional-district vintage crosswalk.
 
 Microcosm calibrates congressional-district (CD) fiscal targets from the IRS SOI
 CD table, whose district geography is the **117th Congress** (the pre-2020-
 apportionment plan, drawn on 2010 geography). The current Microcosm CD surface
 that ``policyengine.py`` consumes is the **119th Congress** (the post-2020-
 apportionment plan). ``congressional_district_vintage`` translates SOI CD facts
 from the old vintage onto the current one through a proportional crosswalk; this
-module *builds that crosswalk* from primary Census sources, so the weights are
-reproducible and cited rather than an opaque artifact.
-
-Method — a single-vintage block overlay, so no 2010<->2020 block bridge is
-needed:
-
-- **Old (117th) district of each 2020 block**: the 2020 Block Assignment File
-  ``CD`` layer (``BlockAssign_ST{fips}_{usps}_CD.txt``, ``BLOCKID|DISTRICT``).
-  The 2020 BAFs were published with the 2020 P.L. 94-171 release and carry the
-  116th-Congress plan (identical district geography to the 117th) expressed on
-  **2020** tabulation blocks.
-- **Current (119th) district of each 2020 block**: the 119th Congressional
-  District Block Equivalency File (``NationalCD119.txt``, ``GEOID,CDFP``) — the
-  same source ``build_us_block_ladder_artifact`` already uses for the current
-  CD surface.
-- **Weight**: 2020 P.L. 94-171 ``POP100`` per block (the block ladder's
+module *builds that crosswalk* from the block -> congressional-district plan
+registry (``cd_plan_registry``), so the weights are reproducible and cited
+rather than an opaque artifact.
+
+Method — a block overlay of two plans on the same 2020 blocks:
+
+- **Old (117th) district of each 2020 block**: the registry's
+  ``117th_congress`` plan. That is the 2020 Block Assignment File ``CD`` layer,
+  which carries the 116th-Congress plans on 2020 blocks, except North
+  Carolina: Census reports it as the only state whose districts changed
+  between the 116th and 117th Congress, and the registry carries its 2019
+  remedial plan onto 2020 blocks (``US_CD_PLAN_REGISTRY.md``). The parsers
+  below read the BAF and BEF layouts directly and remain for callers that
+  need them.
+- **Current (119th) district of each 2020 block**: the registry's
+  ``119th_congress`` plan, the 119th Congressional District Block Equivalency
+  File (``NationalCD119.txt``), which agrees exactly with the block ladder.
+- **Weight**: 2020 P.L. 94-171 ``POP100`` per block, as recorded in the
+  registry (the block ladder's
   :func:`~microcosm.build.us_runtime.block_ladder_sources.parse_pl_geo_blocks`
   convention), because congressional apportionment and equal-population
   redistricting are population operations. Population is the correct default
@@ -39,7 +42,7 @@
 DC non-voting delegate normalize to district ``00`` (the repo-wide convention;
 see ``block_ladder_sources``).
 
-This module is pure and unit-testable. Download orchestration lives in
+This module is pure and unit-testable. The build lives in
 ``tools/build_us_congressional_district_vintage_crosswalk.py``; the derived
 crosswalk is a regenerable build artifact, not a Ledger fact (the fact-vs-
 computed boundary of PolicyEngine/ledger#71).

diff --git a/...src/microcosm/build/us_runtime/data/CONGRESSIONAL_DISTRICT_VINTAGE_CROSSWALK.md b/...src/microcosm/build/us_runtime/data/CONGRESSIONAL_DISTRICT_VINTAGE_CROSSWALK.md
@@ -37,43 +37,44 @@ Regenerate with:
 ```
 uv run --python 3.13 --package microcosm-build --group dev python \
     tools/build_us_congressional_district_vintage_crosswalk.py \
-    --out packages/microcosm-build/src/microcosm/build/us_runtime/data/congressional_district_vintage_crosswalk.csv \
-    --cache-dir ~/.cache/populace-us-geography
+    --cd-plan-registry build/us/us_cd_plan_registry_2020.npz \
+    --out packages/microcosm-build/src/microcosm/build/us_runtime/data/congressional_district_vintage_crosswalk.csv
 ```
 
-The method is a **single-vintage block overlay** — both district assignments are
-read on the same 2020 census blocks, so no 2010↔2020 block bridge is needed:
+The builder reads the pinned US block -> congressional-district plan registry
+(`../US_CD_PLAN_REGISTRY.md`) and refuses any other file. The method is a
+**block overlay** of two of its plans on the same 2020 census blocks:
 
-| Role | Source | Format |
+| Role | Registry plan | Underlying source |
 |---|---|---|
-| Old (117th) district of each 2020 block | 2020 Block Assignment Files, `CD` layer (`BlockAssign_ST{fips}_{usps}_CD.txt`) | `BLOCKID\|DISTRICT` |
-| Current (119th) district of each 2020 block | 119th Congressional District BEF (`NationalCD119.txt`) | `GEOID,CDFP` |
-| Weight | 2020 P.L. 94-171 `POP100` per block (`{usps}geo2020.pl`, summary level 750) | pipe-delimited |
-
-The 2020 Block Assignment Files were published with the 2020 P.L. 94-171 release
-and carry the **116th-Congress plan** — whose district geography is identical to
-the 117th — expressed on **2020** tabulation blocks. Joining that old assignment
-and the current 119th BEF on the same 2020 blocks, weighted by 2020 block
-population, redistributes each old district's population across the current
-districts it overlaps.
+| Old (117th) district of each 2020 block | `117th_congress` | 2020 Block Assignment Files, `CD` layer; North Carolina carried from its 2019 plan |
+| Current (119th) district of each 2020 block | `119th_congress` | 119th Congressional District BEF (`NationalCD119.txt`) |
+| Weight | the registry's `population` | 2020 P.L. 94-171 `POP100` per block |
+
+The 2020 Block Assignment Files carry the **116th-Congress plans** on 2020
+tabulation blocks. Census reports North Carolina as the only state whose
+districts changed between the 116th and 117th Congress. Its 117th districts
+are the 2019 remedial plan, which the registry carries onto 2020 blocks from
+the General Assembly's block file. On 2020 blocks the 2016 and 2019 North
+Carolina plans put only 55% of the state's population in the same district.
+An earlier build read the BAF layer directly and so mapped North Carolina's SOI
+districts through the 2016 plan; only North Carolina's rows changed when the
+builder moved to the registry. Joining the 117th and 119th assignments on the
+same 2020 blocks, weighted by 2020 block population, redistributes each old
+district's population across the current districts it overlaps.
 
 **Population is the correct default basis**: congressional apportionment and
 one-person-one-vote redistricting are population operations, and equal-population
 districts make an at-large state split ≈ evenly (e.g. Montana's old at-large
 district splits 50/50 into MT-01/MT-02). ACS income/tax proxy weights for
 *fiscal* targets are a documented future refinement (#205).
 
-Source URLs and their SHA-256s, plus the crosswalk SHA-256 and full per-state
-population conservation, are recorded in
+The registry's SHA-256 and its 117th-plan known deviations, plus the crosswalk
+SHA-256 and full per-state population conservation, are recorded in
 `congressional_district_vintage_crosswalk.csv.provenance.json` (written by the
-builder). Base source pages:
-
-- 119th CD BEF: `https://www2.census.gov/programs-surveys/decennial/rdo/mapping-files/2025/119-congressional-district-befs/cd119.zip`
-- 2020 Block Assignment Files: `https://www2.census.gov/geo/docs/maps-data/data/baf2020/BlockAssign_ST{fips}_{usps}.zip`
-- 2020 P.L. 94-171 Redistricting Data: `https://www2.census.gov/programs-surveys/decennial/2020/data/01-Redistricting_File--PL_94-171/{state}/{usps}2020.pl.zip`
-
-The exact per-file URLs and their SHA-256s are in the provenance sidecar; these
-are the templates the builder resolves.
+builder). Every underlying Census and General Assembly source file, with its
+URL and SHA-256, is in the registry's receipt,
+`../us_cd_plan_registry.provenance.json`.
 
 ## Geoid conventions
 
@@ -84,7 +85,7 @@ with `block_ladder_sources`), so DC is `…US1100` on both sides.
 
 ## Conservation and coverage (current build)
 
-- 1,444 rows; **436 source districts → 436 current districts** (the full 119th
+- 1,449 rows; **436 source districts → 436 current districts** (the full 119th
   Congress set, including one-district states and DC).
 - Every populated 2020 block in all 50 states + DC is covered:
   **331,449,281 people**, with **zero** unmatched or cross-state population.

diff --git a/...sm-build/src/microcosm/build/us_runtime/data/congressional_district_vintage_crosswalk.csv b/...sm-build/src/microcosm/build/us_runtime/data/congressional_district_vintage_crosswalk.csv
@@ -949,51 +949,56 @@ source_geography_id,target_geography_id,pair_population,weight
 5001700US3627,5001900US3624,337457,0.468630397227021
 5001700US3627,5001900US3625,43930,0.06100609366580937
 5001700US3627,5001900US3626,34520,0.04793831899257317
-5001700US3701,5001900US3701,323902,0.43804103955327933
-5001700US3701,5001900US3703,78733,0.10647753075667438
-5001700US3701,5001900US3704,286624,0.38762673562040106
-5001700US3701,5001900US3713,50174,0.06785469406964525
-5001700US3702,5001900US3701,119881,0.13153875357427358
-5001700US3702,5001900US3702,162205,0.1779785247329856
-5001700US3702,5001900US3704,126509,0.1388112893279817
-5001700US3702,5001900US3713,502779,0.5516714323647591
-5001700US3703,5001900US3701,184554,0.24390933721007071
-5001700US3703,5001900US3703,572096,0.7560906627899293
-5001700US3704,5001900US3702,583465,0.6665406237183888
-5001700US3704,5001900US3704,291898,0.33345937628161115
-5001700US3705,5001900US3705,309843,0.4089197596445083
-5001700US3705,5001900US3706,108247,0.1428605365370174
-5001700US3705,5001900US3710,321815,0.4247199789893508
-5001700US3705,5001900US3711,17806,0.023499724829123506
-5001700US3706,5001900US3704,40640,0.05110541875885762
-5001700US3706,5001900US3705,216290,0.2719879680943237
-5001700US3706,5001900US3709,413171,0.5195688231795267
-5001700US3706,5001900US3713,125118,0.15733778996729203
-5001700US3707,5001900US3701,117333,0.15170592068516106
-5001700US3707,5001900US3703,94842,0.12262614038354124
-5001700US3707,5001900US3707,493650,0.6382656860919754
-5001700US3707,5001900US3713,67599,0.08740225283932229
-5001700US3708,5001900US3706,194142,0.2394999346174628
-5001700US3708,5001900US3707,108801,0.13422047978445967
-5001700US3708,5001900US3708,212801,0.26251828860592097
-5001700US3708,5001900US3709,294870,0.36376129699215654
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-5001700US3709,5001900US3708,526847,0.685180585160687
-5001700US3709,5001900US3712,77291,0.10051930182321368
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-5001700US3712,5001900US3712,668379,0.7381414903991104
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-5001700US3713,5001900US3709,37630,0.047040910466008785
-5001700US3713,5001900US3710,180144,0.2251963267336882
+5001700US3701,5001900US3701,569642,0.8285954916441084
+5001700US3701,5001900US3703,117837,0.1714045083558916
+5001700US3702,5001900US3702,583238,0.6389975666647311
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+5001700US3702,5001900US3713,97595,0.10692541898615048
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+5001700US3703,5001900US3707,9,1.2066753279140203e-05
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+5001700US3704,5001900US3704,513723,0.5854486567307057
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+5001700US3705,5001900US3710,16703,0.022334543460965025
+5001700US3705,5001900US3711,21,2.8080309685701107e-05
+5001700US3705,5001900US3714,456436,0.6103268681763176
+5001700US3706,5001900US3705,264080,0.3271187217496541
+5001700US3706,5001900US3706,256002,0.31711241671218926
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+5001700US3706,5001900US3710,187651,0.23244530163224908
+5001700US3707,5001900US3703,46123,0.05599177416339503
+5001700US3707,5001900US3707,515727,0.6260752707752147
+5001700US3707,5001900US3713,261896,0.3179329550613903
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+5001700US3709,5001900US3712,77576,0.09864273416459614
+5001700US3709,5001900US3714,58926,0.07492809313941157
+5001700US3710,5001900US3705,206892,0.2667416167822936
+5001700US3710,5001900US3706,29960,0.03862681417743322
+5001700US3710,5001900US3709,27,3.48105468221194e-05
+5001700US3710,5001900US3710,538723,0.6945645265056528
+5001700US3710,5001900US3714,25,3.22319877982587e-05
+5001700US3711,5001900US3705,4,5.113670503197962e-06
+5001700US3711,5001900US3711,745649,0.9532508242597643
+5001700US3711,5001900US3714,36564,0.04674406206973257
+5001700US3712,5001900US3708,38059,0.04229374589525411
+5001700US3712,5001900US3712,668094,0.7424314319909587
+5001700US3712,5001900US3714,193720,0.21527482211378718
+5001700US3713,5001900US3704,42,5.442127509047537e-05
+5001700US3713,5001900US3706,358379,0.46436767013451125
+5001700US3713,5001900US3709,335329,0.43450075606700034
+5001700US3713,5001900US3710,2593,0.0033598658645143486
+5001700US3713,5001900US3713,75414,0.09771728665888356
 5001700US3800,5001900US3800,779094,1.0
 5001700US3901,5001900US3901,546669,0.7112991997918158
 5001700US3901,5001900US3908,221881,0.2887008002081842
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1 @@
		Build the packaged 117th->119th congressional-district crosswalk from the CD plan registry, so North Carolina's SOI districts map through its 2019 plan (the 117th Congress's) instead of the 2016 plan in the 2020 BAF layer. Only North Carolina's rows change; the crosswalk sha256 is now a347303f.