diff --git a/packages/web/components/InputsTab.tsx b/packages/web/components/InputsTab.tsx
index cb08dbd..dcbbdab 100644
--- a/packages/web/components/InputsTab.tsx
+++ b/packages/web/components/InputsTab.tsx
@@ -800,9 +800,9 @@ export function InputsTab({ scenarioId, inputsJson, onSaved }: Props) {
         const windEPC = windItems.filter(it => it.category === "EPCOverhead").reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
         const solarCont = solarItems.filter(it => it.category === "Contingency" && it.attribution === "SolarOnly").reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
         const windCont = windItems.filter(it => it.category === "Contingency" && it.attribution === "WindOnly").reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
-        // EPC Margins
-        const epcMarginWTG = [...windItems, ...bessItems].filter(it => it.category === "EPCMargin" && it.attribution === "WindOnly").reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
-        const epcMarginSolarBOS = solarItems.filter(it => it.category === "EPCMargin" && it.attribution === "SolarOnly").reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
+        // EPC Margins - include items with attribution "WindOnly" OR "Common" when wind is enabled
+        const epcMarginWTG = windEnabled ? windItems.filter(it => it.category === "EPCMargin" && (it.attribution === "WindOnly" || it.attribution === "Common")).reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0) : 0;
+        const epcMarginSolarBOS = solarItems.filter(it => it.category === "EPCMargin" && (it.attribution === "SolarOnly" || it.attribution === "Common")).reduce((acc, it) => acc + (computeItemCr(it, solarDcMwp, windMw, bessMwh, 0, effectiveLandAcres) ?? 0), 0);
         // Financing
         const idcRate = gv(inputs, "capex", "interest_rate_annual", 0.09);
         const constrMonths = gv(inputs, "capex", "construction_months", 24);