From 5eb5fb75b9112a9ebba1b0d2f97d6e9a729532a4 Mon Sep 17 00:00:00 2001
From: PavelMakarchuk <pavel.ma99@gmail.com>
Date: Mon, 30 Mar 2026 20:11:54 +0200
Subject: [PATCH 1/3] Fix CTC v22/v23 output mapping to correctly split
 nonrefundable and refundable portions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Previously v22 mapped to ctc_value (total CTC) and v23 was unimplemented.
Per TAXSIM-35 docs, v22 is "Child Tax Credit (as adjusted)" (nonrefundable)
and v23 is "Additional Child Tax Credit" (refundable).

Now: v22 → non_refundable_ctc, v23 → refundable_ctc.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 changelog.d/fix-ctc-v22-v23.fixed.md                      | 1 +
 dashboard/public/config-data.json                         | 2 +-
 ...olicyengine_taxsim_household_with_dependent_output.csv | 4 ++--
 ...xsim_household_with_dependent_single_parent_output.csv | 4 ++--
 output/policyengine_taxsim_joint_household_output.csv     | 6 +++---
 output/policyengine_taxsim_single_household_output.csv    | 6 +++---
 policyengine_taxsim/config/variable_mappings.yaml         | 8 ++++----
 7 files changed, 16 insertions(+), 15 deletions(-)
 create mode 100644 changelog.d/fix-ctc-v22-v23.fixed.md

diff --git a/changelog.d/fix-ctc-v22-v23.fixed.md b/changelog.d/fix-ctc-v22-v23.fixed.md
new file mode 100644
index 0000000..1d3334e
--- /dev/null
+++ b/changelog.d/fix-ctc-v22-v23.fixed.md
@@ -0,0 +1 @@
+Fix CTC v22/v23 output mapping to correctly split nonrefundable and refundable portions.
diff --git a/dashboard/public/config-data.json b/dashboard/public/config-data.json
index d424d0d..03c23e4 100644
--- a/dashboard/public/config-data.json
+++ b/dashboard/public/config-data.json
@@ -280,5 +280,5 @@
       }
     ]
   },
-  "lastUpdated": "2026-03-24T15:14:08.434Z"
+  "lastUpdated": "2026-03-30T13:59:03.214Z"
 }
\ No newline at end of file
diff --git a/output/policyengine_taxsim_household_with_dependent_output.csv b/output/policyengine_taxsim_household_with_dependent_output.csv
index 0c93453..f41873b 100644
--- a/output/policyengine_taxsim_household_with_dependent_output.csv
+++ b/output/policyengine_taxsim_household_with_dependent_output.csv
@@ -1,2 +1,2 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
-6,2023,39,3956.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,27700.0,0.0,2486.7,0.0,0.0,53300.0,5956.0,2000.0,0.0,0.0,81000.0,0.0,5956.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,12.0,3.0701
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
+6,2023,39,3956.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,27700.0,0.0,2486.7,0.0,0.0,53300.0,5956.0,2000.0,0.0,0.0,0.0,81000.0,0.0,5956.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,3.0701,12.0
diff --git a/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv b/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
index 2c3932c..c521f33 100644
--- a/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
+++ b/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
@@ -1,2 +1,2 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
-6,2023,39,4945.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,20800.0,0.0,2486.7,0.0,0.0,60200.0,6945.0,2000.0,0.0,0.0,81000.0,0.0,6945.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,3.0701,22.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
+6,2023,39,4945.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,20800.0,0.0,2486.7,0.0,0.0,60200.0,6945.0,2000.0,0.0,0.0,0.0,81000.0,0.0,6945.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,22.0,3.0701
diff --git a/output/policyengine_taxsim_joint_household_output.csv b/output/policyengine_taxsim_joint_household_output.csv
index aa29fb9..20e402e 100644
--- a/output/policyengine_taxsim_joint_household_output.csv
+++ b/output/policyengine_taxsim_joint_household_output.csv
@@ -1,3 +1,3 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
-999,2023,44,1716.0,0.0,0.0,6043.5,79000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,51300.0,5716.0,4000.0,0.0,0.0,79000.0,0.0,5716.0,6043.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1145.5,0.0,0.0,12.0
-11,2023,44,1476.0,0.0,0.0,5890.5,77000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,49300.0,5476.0,4000.0,0.0,0.0,77000.0,0.0,5476.0,5890.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1116.5,0.0,0.0,12.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
+999,2023,44,1716.0,0.0,0.0,6043.5,79000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,51300.0,5716.0,4000.0,0.0,0.0,0.0,79000.0,0.0,5716.0,6043.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1145.5,0.0,12.0,0.0
+11,2023,44,1476.0,0.0,0.0,5890.5,77000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,49300.0,5476.0,4000.0,0.0,0.0,0.0,77000.0,0.0,5476.0,5890.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1116.5,0.0,12.0,0.0
diff --git a/output/policyengine_taxsim_single_household_output.csv b/output/policyengine_taxsim_single_household_output.csv
index f14a873..9160a03 100644
--- a/output/policyengine_taxsim_single_household_output.csv
+++ b/output/policyengine_taxsim_single_household_output.csv
@@ -1,3 +1,3 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
-999,2021,3,2775.0,1008.87,0.0,3748.5,49000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,36450.0,4175.0,0.0,0.0,0.0,49000.0,0.0,4175.0,3748.5,49000.0,12550.0,1020.0,36450.0,0.0,0.0,0.0,0.0,0.0,0.0,710.5,1400.0,3.34,12.0
-11,2021,3,2535.0,942.07,0.0,3595.5,47000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,34450.0,3935.0,0.0,0.0,0.0,47000.0,0.0,3935.0,3595.5,47000.0,12550.0,1020.0,34450.0,0.0,0.0,0.0,0.0,0.0,0.0,681.5,1400.0,3.34,12.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
+999,2021,3,2775.0,1008.87,0.0,3748.5,49000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,36450.0,4175.0,0.0,0.0,0.0,0.0,49000.0,0.0,4175.0,3748.5,49000.0,12550.0,1020.0,36450.0,0.0,0.0,0.0,0.0,0.0,0.0,710.5,1400.0,3.34,12.0
+11,2021,3,2535.0,942.07,0.0,3595.5,47000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,34450.0,3935.0,0.0,0.0,0.0,0.0,47000.0,0.0,3935.0,3595.5,47000.0,12550.0,1020.0,34450.0,0.0,0.0,0.0,0.0,0.0,0.0,681.5,1400.0,3.34,12.0
diff --git a/policyengine_taxsim/config/variable_mappings.yaml b/policyengine_taxsim/config/variable_mappings.yaml
index 3ac6306..f3233d8 100644
--- a/policyengine_taxsim/config/variable_mappings.yaml
+++ b/policyengine_taxsim/config/variable_mappings.yaml
@@ -249,7 +249,7 @@ policyengine_to_taxsim:
     full_text_group: "Federal Tax Calculation"
     group_column: 1
   v22:
-    variable: ctc_value
+    variable: non_refundable_ctc
     implemented: true
     idtl:
       - full: 2
@@ -259,12 +259,12 @@ policyengine_to_taxsim:
     full_text_group: "Federal Tax Calculation"
     group_column: 1
   v23:
-    variable: na_pe
-    implemented: false
+    variable: refundable_ctc
+    implemented: true
     idtl:
       - full: 2
       - full_text: 5
-    text_description: "Reserved"
+    text_description: "Additional Child Tax Credit"
     group_order: 3
     full_text_group: "Federal Tax Calculation"
     group_column: 1

From fdc43b428a324dddcbff365a5ce6c9c101145eb9 Mon Sep 17 00:00:00 2001
From: PavelMakarchuk <pavel.ma99@gmail.com>
Date: Tue, 31 Mar 2026 12:16:46 +0200
Subject: [PATCH 2/3] Revert "Fix CTC v22/v23 output mapping to correctly split
 nonrefundable and refundable portions"

This reverts commit 5eb5fb75b9112a9ebba1b0d2f97d6e9a729532a4.
---
 changelog.d/fix-ctc-v22-v23.fixed.md                      | 1 -
 dashboard/public/config-data.json                         | 2 +-
 ...olicyengine_taxsim_household_with_dependent_output.csv | 4 ++--
 ...xsim_household_with_dependent_single_parent_output.csv | 4 ++--
 output/policyengine_taxsim_joint_household_output.csv     | 6 +++---
 output/policyengine_taxsim_single_household_output.csv    | 6 +++---
 policyengine_taxsim/config/variable_mappings.yaml         | 8 ++++----
 7 files changed, 15 insertions(+), 16 deletions(-)
 delete mode 100644 changelog.d/fix-ctc-v22-v23.fixed.md

diff --git a/changelog.d/fix-ctc-v22-v23.fixed.md b/changelog.d/fix-ctc-v22-v23.fixed.md
deleted file mode 100644
index 1d3334e..0000000
--- a/changelog.d/fix-ctc-v22-v23.fixed.md
+++ /dev/null
@@ -1 +0,0 @@
-Fix CTC v22/v23 output mapping to correctly split nonrefundable and refundable portions.
diff --git a/dashboard/public/config-data.json b/dashboard/public/config-data.json
index 03c23e4..d424d0d 100644
--- a/dashboard/public/config-data.json
+++ b/dashboard/public/config-data.json
@@ -280,5 +280,5 @@
       }
     ]
   },
-  "lastUpdated": "2026-03-30T13:59:03.214Z"
+  "lastUpdated": "2026-03-24T15:14:08.434Z"
 }
\ No newline at end of file
diff --git a/output/policyengine_taxsim_household_with_dependent_output.csv b/output/policyengine_taxsim_household_with_dependent_output.csv
index f41873b..0c93453 100644
--- a/output/policyengine_taxsim_household_with_dependent_output.csv
+++ b/output/policyengine_taxsim_household_with_dependent_output.csv
@@ -1,2 +1,2 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
-6,2023,39,3956.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,27700.0,0.0,2486.7,0.0,0.0,53300.0,5956.0,2000.0,0.0,0.0,0.0,81000.0,0.0,5956.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,3.0701,12.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
+6,2023,39,3956.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,27700.0,0.0,2486.7,0.0,0.0,53300.0,5956.0,2000.0,0.0,0.0,81000.0,0.0,5956.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,12.0,3.0701
diff --git a/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv b/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
index c521f33..2c3932c 100644
--- a/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
+++ b/output/policyengine_taxsim_household_with_dependent_single_parent_output.csv
@@ -1,2 +1,2 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
-6,2023,39,4945.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,20800.0,0.0,2486.7,0.0,0.0,60200.0,6945.0,2000.0,0.0,0.0,0.0,81000.0,0.0,6945.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,22.0,3.0701
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
+6,2023,39,4945.0,2486.7,0.0,6196.5,81000.0,0.0,0.0,20800.0,0.0,2486.7,0.0,0.0,60200.0,6945.0,2000.0,0.0,0.0,81000.0,0.0,6945.0,6196.5,81000.0,0.0,0.0,81000.0,0.0,0.0,0.0,0.0,0.0,0.0,1174.5,0.0,3.0701,22.0
diff --git a/output/policyengine_taxsim_joint_household_output.csv b/output/policyengine_taxsim_joint_household_output.csv
index 20e402e..aa29fb9 100644
--- a/output/policyengine_taxsim_joint_household_output.csv
+++ b/output/policyengine_taxsim_joint_household_output.csv
@@ -1,3 +1,3 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,frate,srate
-999,2023,44,1716.0,0.0,0.0,6043.5,79000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,51300.0,5716.0,4000.0,0.0,0.0,0.0,79000.0,0.0,5716.0,6043.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1145.5,0.0,12.0,0.0
-11,2023,44,1476.0,0.0,0.0,5890.5,77000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,49300.0,5476.0,4000.0,0.0,0.0,0.0,77000.0,0.0,5476.0,5890.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1116.5,0.0,12.0,0.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
+999,2023,44,1716.0,0.0,0.0,6043.5,79000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,51300.0,5716.0,4000.0,0.0,0.0,79000.0,0.0,5716.0,6043.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1145.5,0.0,0.0,12.0
+11,2023,44,1476.0,0.0,0.0,5890.5,77000.0,0.0,0.0,27700.0,0.0,1927.2,0.0,0.0,49300.0,5476.0,4000.0,0.0,0.0,77000.0,0.0,5476.0,5890.5,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,1116.5,0.0,0.0,12.0
diff --git a/output/policyengine_taxsim_single_household_output.csv b/output/policyengine_taxsim_single_household_output.csv
index 9160a03..f14a873 100644
--- a/output/policyengine_taxsim_single_household_output.csv
+++ b/output/policyengine_taxsim_single_household_output.csv
@@ -1,3 +1,3 @@
-taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v23,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
-999,2021,3,2775.0,1008.87,0.0,3748.5,49000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,36450.0,4175.0,0.0,0.0,0.0,0.0,49000.0,0.0,4175.0,3748.5,49000.0,12550.0,1020.0,36450.0,0.0,0.0,0.0,0.0,0.0,0.0,710.5,1400.0,3.34,12.0
-11,2021,3,2535.0,942.07,0.0,3595.5,47000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,34450.0,3935.0,0.0,0.0,0.0,0.0,47000.0,0.0,3935.0,3595.5,47000.0,12550.0,1020.0,34450.0,0.0,0.0,0.0,0.0,0.0,0.0,681.5,1400.0,3.34,12.0
+taxsimid,year,state,fiitax,siitax,fica,tfica,v10,v11,v12,v13,v14,v17,qbid,niit,v18,v19,v22,v24,v25,v26,v27,v28,v29,v32,v34,v35,v36,v37,v38,v39,v40,v42,v43,v44,cares,srate,frate
+999,2021,3,2775.0,1008.87,0.0,3748.5,49000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,36450.0,4175.0,0.0,0.0,0.0,49000.0,0.0,4175.0,3748.5,49000.0,12550.0,1020.0,36450.0,0.0,0.0,0.0,0.0,0.0,0.0,710.5,1400.0,3.34,12.0
+11,2021,3,2535.0,942.07,0.0,3595.5,47000.0,0.0,0.0,12550.0,0.0,1020.0,0.0,0.0,34450.0,3935.0,0.0,0.0,0.0,47000.0,0.0,3935.0,3595.5,47000.0,12550.0,1020.0,34450.0,0.0,0.0,0.0,0.0,0.0,0.0,681.5,1400.0,3.34,12.0
diff --git a/policyengine_taxsim/config/variable_mappings.yaml b/policyengine_taxsim/config/variable_mappings.yaml
index f3233d8..3ac6306 100644
--- a/policyengine_taxsim/config/variable_mappings.yaml
+++ b/policyengine_taxsim/config/variable_mappings.yaml
@@ -249,7 +249,7 @@ policyengine_to_taxsim:
     full_text_group: "Federal Tax Calculation"
     group_column: 1
   v22:
-    variable: non_refundable_ctc
+    variable: ctc_value
     implemented: true
     idtl:
       - full: 2
@@ -259,12 +259,12 @@ policyengine_to_taxsim:
     full_text_group: "Federal Tax Calculation"
     group_column: 1
   v23:
-    variable: refundable_ctc
-    implemented: true
+    variable: na_pe
+    implemented: false
     idtl:
       - full: 2
       - full_text: 5
-    text_description: "Additional Child Tax Credit"
+    text_description: "Reserved"
     group_order: 3
     full_text_group: "Federal Tax Calculation"
     group_column: 1

From 1f49197fa20353ca22e70867b51057e6634c2a3c Mon Sep 17 00:00:00 2001
From: PavelMakarchuk <pavel.ma99@gmail.com>
Date: Tue, 31 Mar 2026 12:23:37 +0200
Subject: [PATCH 3/3] Add statefip (FIPS code) input support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

TAXSIM-35 accepts both SOI codes (state column) and FIPS codes
(statefip column). When statefip is provided and state is 0 or
missing, automatically convert FIPS→SOI. This prevents users from
accidentally passing FIPS codes in the state column and getting
wrong state tax results.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 changelog.d/add-statefip-support.added.md  |  1 +
 dashboard/src/components/CsvRunner.jsx     |  2 +-
 policyengine_taxsim/api.py                 |  1 +
 policyengine_taxsim/core/utils.py          |  3 +++
 policyengine_taxsim/runners/base_runner.py | 13 +++++++++++++
 5 files changed, 19 insertions(+), 1 deletion(-)
 create mode 100644 changelog.d/add-statefip-support.added.md

diff --git a/changelog.d/add-statefip-support.added.md b/changelog.d/add-statefip-support.added.md
new file mode 100644
index 0000000..41f9fbc
--- /dev/null
+++ b/changelog.d/add-statefip-support.added.md
@@ -0,0 +1 @@
+Add statefip (FIPS code) input support, matching TAXSIM-35 behavior.
diff --git a/dashboard/src/components/CsvRunner.jsx b/dashboard/src/components/CsvRunner.jsx
index 5fd7bdd..3180af0 100644
--- a/dashboard/src/components/CsvRunner.jsx
+++ b/dashboard/src/components/CsvRunner.jsx
@@ -40,7 +40,7 @@ const SAMPLE_DATASETS = [
 const fmt = (n) => Number(n).toLocaleString();
 
 const KNOWN_COLUMNS = new Set([
-  'taxsimid', 'year', 'state', 'mstat', 'page', 'sage',
+  'taxsimid', 'year', 'state', 'statefip', 'mstat', 'page', 'sage',
   'dependent_exemption', 'depx', 'pwages', 'swages',
   'psemp', 'ssemp', 'dividends', 'intrec', 'stcg', 'ltcg',
   'otherprop', 'nonprop', 'pensions', 'gssi',
diff --git a/policyengine_taxsim/api.py b/policyengine_taxsim/api.py
index 818cbc0..e4550b4 100644
--- a/policyengine_taxsim/api.py
+++ b/policyengine_taxsim/api.py
@@ -49,6 +49,7 @@
     "taxsimid",
     "year",
     "state",
+    "statefip",
     "mstat",
     "page",
     "sage",
diff --git a/policyengine_taxsim/core/utils.py b/policyengine_taxsim/core/utils.py
index 0a29b69..b489a8c 100644
--- a/policyengine_taxsim/core/utils.py
+++ b/policyengine_taxsim/core/utils.py
@@ -284,3 +284,6 @@ def get_ordinal(n):
     50: 55,  # Wisconsin
     51: 56,  # Wyoming
 }
+
+# Reverse mapping: FIPS → SOI (for statefip input support)
+FIPS_TO_SOI_MAP = {fips: soi for soi, fips in SOI_TO_FIPS_MAP.items()}
diff --git a/policyengine_taxsim/runners/base_runner.py b/policyengine_taxsim/runners/base_runner.py
index 33889fe..dc490d2 100644
--- a/policyengine_taxsim/runners/base_runner.py
+++ b/policyengine_taxsim/runners/base_runner.py
@@ -5,8 +5,10 @@
 
 try:
     from ..core.io import write_output
+    from ..core.utils import FIPS_TO_SOI_MAP
 except ImportError:
     from policyengine_taxsim.core.io import write_output
+    from policyengine_taxsim.core.utils import FIPS_TO_SOI_MAP
 
 
 class BaseTaxRunner(ABC):
@@ -39,6 +41,17 @@ def _validate_input(self):
         if "year" not in self.input_df.columns:
             raise ValueError("Input data must contain a 'year' column")
 
+        # Convert statefip (FIPS) to state (SOI) per row.
+        # Matches TAXSIM-35 behavior: for each record, if state==0
+        # and statefip is set, convert FIPS→SOI.
+        if "statefip" in self.input_df.columns:
+            if "state" not in self.input_df.columns:
+                self.input_df["state"] = 0
+            fips_vals = self.input_df["statefip"].astype(int)
+            soi_from_fips = fips_vals.map(FIPS_TO_SOI_MAP).fillna(0).astype(int)
+            use_fips = (self.input_df["state"] == 0) & (fips_vals > 0)
+            self.input_df.loc[use_fips, "state"] = soi_from_fips[use_fips]
+
         # Auto-assign taxsimid if not present
         if "taxsimid" not in self.input_df.columns:
             # Assign sequential IDs starting from 1