diff --git a/packages/core/components/DataTable/DataTable.tsx b/packages/core/components/DataTable/DataTable.tsx
index 5274bc822..5d6daab6d 100644
--- a/packages/core/components/DataTable/DataTable.tsx
+++ b/packages/core/components/DataTable/DataTable.tsx
@@ -27,6 +27,7 @@ import './data-table.css'
 import _ from 'lodash'
 import { getDataSeriesColumns } from './helpers/getDataSeriesColumns'
 import { getMapDataTableColumnKeys } from './helpers/getMapDataTableColumnKeys'
+import { addOptionalFullGeoNameColumn } from './helpers/addOptionalFullGeoNameColumn'
 
 export type DataTableProps = {
   colorScale?: Function
@@ -327,27 +328,12 @@ const DataTable = (props: DataTableProps) => {
         return newRow
       })
 
-      // only use fullGeoName on County maps and no other
-      if (config.general?.geoType === 'us-county' || config.table.showFullGeoNameInCSV) {
-        // Add column for full Geo name along with State
-        return csvDataUpdated.map((row, index) => {
-          const originalRow = csvData[index]
-          if (!originalRow) {
-            console.warn('Data mismatch: originalRow missing.', {
-              index,
-              csvDataLength: csvData.length,
-              csvDataUpdatedLength: csvDataUpdated.length
-            })
-            return row
-          }
-          return {
-            FullGeoName: formatLegendLocation(originalRow[config.columns.geo.name]),
-            ...row
-          }
-        })
-      } else {
-        return csvDataUpdated
-      }
+      return addOptionalFullGeoNameColumn({
+        config,
+        csvData,
+        csvDataUpdated,
+        formatLegendLocation
+      })
     }
 
     const getMediaControlsClasses = (belowTable, hasDownloadLink) => {
diff --git a/packages/core/components/DataTable/helpers/addOptionalFullGeoNameColumn.ts b/packages/core/components/DataTable/helpers/addOptionalFullGeoNameColumn.ts
new file mode 100644
index 000000000..00d4ef2b0
--- /dev/null
+++ b/packages/core/components/DataTable/helpers/addOptionalFullGeoNameColumn.ts
@@ -0,0 +1,36 @@
+type AddOptionalFullGeoNameColumnArgs = {
+  config: any
+  csvData: Record<string, any>[]
+  csvDataUpdated: Record<string, any>[]
+  formatLegendLocation?: (key: string) => string
+}
+
+export const addOptionalFullGeoNameColumn = ({
+  config,
+  csvData,
+  csvDataUpdated,
+  formatLegendLocation
+}: AddOptionalFullGeoNameColumnArgs) => {
+  if (!config?.table?.showFullGeoNameInCSV || typeof formatLegendLocation !== 'function') {
+    return csvDataUpdated
+  }
+
+  return csvDataUpdated.map((row, index) => {
+    const originalRow = csvData[index]
+    if (!originalRow) {
+      console.warn('Data mismatch: originalRow missing.', {
+        index,
+        csvDataLength: csvData.length,
+        csvDataUpdatedLength: csvDataUpdated.length
+      })
+      return row
+    }
+
+    return {
+      FullGeoName: formatLegendLocation(originalRow[config.columns.geo.name]),
+      ...row
+    }
+  })
+}
+
+export default addOptionalFullGeoNameColumn
diff --git a/packages/core/components/DataTable/helpers/tests/addOptionalFullGeoNameColumn.test.ts b/packages/core/components/DataTable/helpers/tests/addOptionalFullGeoNameColumn.test.ts
new file mode 100644
index 000000000..b9fb53a5f
--- /dev/null
+++ b/packages/core/components/DataTable/helpers/tests/addOptionalFullGeoNameColumn.test.ts
@@ -0,0 +1,69 @@
+import { describe, expect, it, vi } from 'vitest'
+import { addOptionalFullGeoNameColumn } from '../addOptionalFullGeoNameColumn'
+
+describe('addOptionalFullGeoNameColumn', () => {
+  const csvData = [{ geo: '01001', value: 1 }]
+  const csvDataUpdated = [{ Geo: '01001', Value: 1 }]
+  const formatLegendLocation = vi.fn((key: string) => `AL, ${key}`)
+
+  it('does not add FullGeoName for county maps when the toggle is off', () => {
+    const result = addOptionalFullGeoNameColumn({
+      config: {
+        general: { geoType: 'us-county' },
+        table: { showFullGeoNameInCSV: false },
+        columns: { geo: { name: 'geo' } }
+      },
+      csvData,
+      csvDataUpdated,
+      formatLegendLocation
+    })
+
+    expect(result).toEqual(csvDataUpdated)
+    expect(result[0]).not.toHaveProperty('FullGeoName')
+  })
+
+  it('adds FullGeoName for county maps when the toggle is on', () => {
+    const result = addOptionalFullGeoNameColumn({
+      config: {
+        general: { geoType: 'us-county' },
+        table: { showFullGeoNameInCSV: true },
+        columns: { geo: { name: 'geo' } }
+      },
+      csvData,
+      csvDataUpdated,
+      formatLegendLocation
+    })
+
+    expect(result).toEqual([{ FullGeoName: 'AL, 01001', Geo: '01001', Value: 1 }])
+  })
+
+  it('does not add FullGeoName for non-county maps when the toggle is off', () => {
+    const result = addOptionalFullGeoNameColumn({
+      config: {
+        general: { geoType: 'us' },
+        table: { showFullGeoNameInCSV: false },
+        columns: { geo: { name: 'geo' } }
+      },
+      csvData,
+      csvDataUpdated,
+      formatLegendLocation
+    })
+
+    expect(result).toEqual(csvDataUpdated)
+  })
+
+  it('adds FullGeoName for non-county maps when the toggle is on', () => {
+    const result = addOptionalFullGeoNameColumn({
+      config: {
+        general: { geoType: 'us' },
+        table: { showFullGeoNameInCSV: true },
+        columns: { geo: { name: 'geo' } }
+      },
+      csvData,
+      csvDataUpdated,
+      formatLegendLocation
+    })
+
+    expect(result).toEqual([{ FullGeoName: 'AL, 01001', Geo: '01001', Value: 1 }])
+  })
+})
diff --git a/packages/core/helpers/ver/4.26.4.ts b/packages/core/helpers/ver/4.26.4.ts
index 086bc3770..e03a91e9b 100644
--- a/packages/core/helpers/ver/4.26.4.ts
+++ b/packages/core/helpers/ver/4.26.4.ts
@@ -61,11 +61,19 @@ const applyMarkupVariableSourceTypes = config => {
   })
 }
 
+const enableFullGeoNameCsvOnLegacyCountyMaps = config => {
+  if (config.type === 'map' && config.general?.geoType === 'us-county') {
+    config.table = config.table || {}
+    config.table.showFullGeoNameInCSV = true
+  }
+}
+
 const run_4_26_4_migrations = config => {
   disableExtraChartVisualSettings(config)
   addMarkupIncludeStyle(config)
   applyWaffleValueDescriptorDefaults(config)
   applyMarkupVariableSourceTypes(config)
+  enableFullGeoNameCsvOnLegacyCountyMaps(config)
 
   if (config.type === 'dashboard' && config.visualizations) {
     Object.values((config as DashboardConfig).visualizations).forEach(visualization => {
diff --git a/packages/core/helpers/ver/tests/4.26.4.test.ts b/packages/core/helpers/ver/tests/4.26.4.test.ts
index e534bb54c..7ade8457f 100644
--- a/packages/core/helpers/ver/tests/4.26.4.test.ts
+++ b/packages/core/helpers/ver/tests/4.26.4.test.ts
@@ -377,4 +377,56 @@ describe('update_4_26_4', () => {
     expect(result.visualizations.nestedChart.markupVariables[0].sourceType).toBe('column')
     expect(result.visualizations.nestedChart.markupVariables[1].sourceType).toBe('metadata')
   })
+
+  it('enables full geo name CSV export for legacy county maps', () => {
+    const config: any = {
+      type: 'map',
+      version: '4.26.3',
+      general: { geoType: 'us-county' },
+      table: { showFullGeoNameInCSV: false }
+    }
+
+    const result = update_4_26_4(config)
+
+    expect(result.table.showFullGeoNameInCSV).toBe(true)
+    expect(result.version).toBe('4.26.4')
+    expect(config.table.showFullGeoNameInCSV).toBe(false)
+  })
+
+  it('does not change non-county map CSV full geo name settings', () => {
+    const config: any = {
+      type: 'map',
+      version: '4.26.3',
+      general: { geoType: 'us' },
+      table: { showFullGeoNameInCSV: false }
+    }
+
+    const result = update_4_26_4(config)
+
+    expect(result.table.showFullGeoNameInCSV).toBe(false)
+  })
+
+  it('enables full geo name CSV export for county maps inside dashboards', () => {
+    const config: any = {
+      type: 'dashboard',
+      version: '4.26.3',
+      visualizations: {
+        countyMap: {
+          type: 'map',
+          general: { geoType: 'us-county' },
+          table: { showFullGeoNameInCSV: false }
+        },
+        usMap: {
+          type: 'map',
+          general: { geoType: 'us' },
+          table: { showFullGeoNameInCSV: false }
+        }
+      }
+    }
+
+    const result = update_4_26_4(config)
+
+    expect(result.visualizations.countyMap.table.showFullGeoNameInCSV).toBe(true)
+    expect(result.visualizations.usMap.table.showFullGeoNameInCSV).toBe(false)
+  })
 })