diff --git a/app/props/[propId]/prop-page-header.tsx b/app/props/[propId]/prop-page-header.tsx
index 1406455..78ca1c0 100644
--- a/app/props/[propId]/prop-page-header.tsx
+++ b/app/props/[propId]/prop-page-header.tsx
@@ -8,6 +8,8 @@ import { Button } from "@/components/ui/button";
 import { ChevronLeft, CheckCircle2 } from "lucide-react";
 import { ResolutionDialog } from "@/components/dialogs/resolution-dialog";
 import { MarkdownRenderer } from "@/components/markdown";
+import { PropStatusBadge } from "@/components/ui/prop-status-badge";
+import { getPropStatusFromProp } from "@/lib/prop-status";
 
 interface PropPageHeaderProps {
   prop: VProp;
@@ -41,22 +43,7 @@ export default function PropPageHeader({
                 {prop.category_name}
               </Badge>
             )}
-            <Badge
-              variant={
-                prop.resolution === null
-                  ? "outline"
-                  : prop.resolution
-                    ? "default"
-                    : "destructive"
-              }
-              className="text-xs"
-            >
-              {prop.resolution === null
-                ? "Unresolved"
-                : prop.resolution
-                  ? "Yes"
-                  : "No"}
-            </Badge>
+            <PropStatusBadge status={getPropStatusFromProp(prop)} />
           </div>
           {canResolve && (
             <Button
diff --git a/components/forecast-card/forecast-card.tsx b/components/forecast-card/forecast-card.tsx
index 5bd70e7..479f3a1 100644
--- a/components/forecast-card/forecast-card.tsx
+++ b/components/forecast-card/forecast-card.tsx
@@ -3,6 +3,8 @@
 import { PropWithUserForecast } from "@/types/db_types";
 import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
+import { PropStatusBadge } from "@/components/ui/prop-status-badge";
+import { getPropStatusFromProp } from "@/lib/prop-status";
 import {
   Tooltip,
   TooltipContent,
@@ -57,14 +59,7 @@ export function ForecastCard({ prop, showCommunityAvg }: ForecastCardProps) {
                 <Badge variant="secondary" className="text-xs font-medium">
                   {prop.category_name}
                 </Badge>
-                {prop.resolution !== null && (
-                  <Badge
-                    variant={prop.resolution ? "default" : "destructive"}
-                    className="text-xs"
-                  >
-                    {prop.resolution ? "Yes" : "No"}
-                  </Badge>
-                )}
+                <PropStatusBadge status={getPropStatusFromProp(prop)} />
               </div>
               <Link href={`/props/${prop.prop_id}`}>
                 <Button variant="ghost" size="sm" className="h-7 px-2">
@@ -134,14 +129,7 @@ export function ForecastCard({ prop, showCommunityAvg }: ForecastCardProps) {
               <Badge variant="secondary" className="text-xs font-medium">
                 {prop.category_name}
               </Badge>
-              {prop.resolution !== null && (
-                <Badge
-                  variant={prop.resolution ? "default" : "destructive"}
-                  className="text-xs"
-                >
-                  {prop.resolution ? "Yes" : "No"}
-                </Badge>
-              )}
+              <PropStatusBadge status={getPropStatusFromProp(prop)} />
             </div>
             <Link href={`/props/${prop.prop_id}`}>
               <Button variant="ghost" size="sm" className="h-7 px-2">
diff --git a/components/ui/prop-status-badge.stories.tsx b/components/ui/prop-status-badge.stories.tsx
new file mode 100644
index 0000000..6c9d9e3
--- /dev/null
+++ b/components/ui/prop-status-badge.stories.tsx
@@ -0,0 +1,107 @@
+import type { Meta, StoryObj } from "@storybook/react-vite";
+import { PropStatusBadge } from "./prop-status-badge";
+
+const meta = {
+  title: "UI/PropStatusBadge",
+  component: PropStatusBadge,
+  parameters: {
+    layout: "centered",
+  },
+  tags: ["autodocs"],
+  argTypes: {
+    status: {
+      control: "select",
+      options: ["open", "closed", "resolved-yes", "resolved-no"],
+      description: "The lifecycle status of the prop",
+    },
+    label: {
+      control: "text",
+      description: "Custom label (defaults to status name)",
+    },
+  },
+} satisfies Meta<typeof PropStatusBadge>;
+
+export default meta;
+type Story = StoryObj<typeof meta>;
+
+// Individual status stories
+export const Open: Story = {
+  args: {
+    status: "open",
+  },
+};
+
+export const Closed: Story = {
+  args: {
+    status: "closed",
+  },
+};
+
+export const ResolvedYes: Story = {
+  args: {
+    status: "resolved-yes",
+  },
+};
+
+export const ResolvedNo: Story = {
+  args: {
+    status: "resolved-no",
+  },
+};
+
+// All states comparison
+export const AllStates: Story = {
+  args: {
+    status: "open",
+  },
+  render: () => (
+    <div className="flex flex-wrap gap-2">
+      <PropStatusBadge status="open" />
+      <PropStatusBadge status="closed" />
+      <PropStatusBadge status="resolved-yes" />
+      <PropStatusBadge status="resolved-no" />
+    </div>
+  ),
+};
+
+// In context - showing how it might appear in a card
+export const InContext: Story = {
+  args: {
+    status: "open",
+  },
+  render: () => (
+    <div className="bg-card rounded-lg border border-border p-4 w-80">
+      <div className="flex items-center justify-between gap-2 mb-2">
+        <span className="text-xs text-muted-foreground">Category</span>
+        <PropStatusBadge status="open" />
+      </div>
+      <h3 className="font-medium text-foreground">
+        Will the temperature exceed 30°C tomorrow?
+      </h3>
+      <p className="text-sm text-muted-foreground mt-1">
+        Based on local weather station data
+      </p>
+    </div>
+  ),
+};
+
+// Resolved in context
+export const ResolvedInContext: Story = {
+  args: {
+    status: "resolved-yes",
+  },
+  render: () => (
+    <div className="bg-card rounded-lg border border-border p-4 w-80">
+      <div className="flex items-center justify-between gap-2 mb-2">
+        <span className="text-xs text-muted-foreground">Category</span>
+        <PropStatusBadge status="resolved-yes" />
+      </div>
+      <h3 className="font-medium text-foreground">
+        Will the temperature exceed 30°C tomorrow?
+      </h3>
+      <p className="text-sm text-muted-foreground mt-1">
+        Based on local weather station data
+      </p>
+    </div>
+  ),
+};
diff --git a/components/ui/prop-status-badge.tsx b/components/ui/prop-status-badge.tsx
new file mode 100644
index 0000000..d3f9710
--- /dev/null
+++ b/components/ui/prop-status-badge.tsx
@@ -0,0 +1,59 @@
+import * as React from "react";
+import { cva, type VariantProps } from "class-variance-authority";
+import { cn } from "@/lib/utils";
+import { PropStatus, getPropStatusLabel } from "@/lib/prop-status";
+
+const propStatusBadgeVariants = cva(
+  "inline-flex items-center rounded-md border px-2.5 py-0.5 text-xs font-semibold transition-colors",
+  {
+    variants: {
+      status: {
+        open: "border-green-200 bg-green-100 text-green-700 dark:border-green-800 dark:bg-green-950 dark:text-green-400",
+        closed: "border-transparent bg-secondary text-secondary-foreground",
+        "resolved-yes":
+          "border-transparent bg-primary text-primary-foreground shadow-sm",
+        "resolved-no":
+          "border-transparent bg-destructive text-destructive-foreground shadow-sm",
+      },
+    },
+    defaultVariants: {
+      status: "open",
+    },
+  },
+);
+
+export interface PropStatusBadgeProps
+  extends
+    Omit<React.HTMLAttributes<HTMLDivElement>, "children">,
+    VariantProps<typeof propStatusBadgeVariants> {
+  status: PropStatus;
+  /** Optional custom label (defaults to status label) */
+  label?: string;
+}
+
+/**
+ * Badge component for displaying prop lifecycle status
+ *
+ * @example
+ * <PropStatusBadge status="open" />
+ * <PropStatusBadge status="resolved-yes" />
+ */
+function PropStatusBadge({
+  status,
+  label,
+  className,
+  ...props
+}: PropStatusBadgeProps) {
+  const displayLabel = label ?? getPropStatusLabel(status);
+
+  return (
+    <div
+      className={cn(propStatusBadgeVariants({ status }), className)}
+      {...props}
+    >
+      {displayLabel}
+    </div>
+  );
+}
+
+export { PropStatusBadge, propStatusBadgeVariants };
diff --git a/lib/prop-status.test.ts b/lib/prop-status.test.ts
new file mode 100644
index 0000000..2c7a640
--- /dev/null
+++ b/lib/prop-status.test.ts
@@ -0,0 +1,121 @@
+import { describe, it, expect } from "vitest";
+import {
+  getPropStatus,
+  getPropStatusFromProp,
+  getPropStatusLabel,
+  PropStatus,
+} from "./prop-status";
+
+describe("getPropStatus", () => {
+  const now = new Date("2024-06-15T12:00:00Z");
+
+  describe("resolution states", () => {
+    it("should return resolved-yes when resolution is true", () => {
+      const pastDate = new Date("2024-06-10T12:00:00Z");
+      expect(getPropStatus(pastDate, true, { currentDate: now })).toBe(
+        "resolved-yes",
+      );
+    });
+
+    it("should return resolved-no when resolution is false", () => {
+      const pastDate = new Date("2024-06-10T12:00:00Z");
+      expect(getPropStatus(pastDate, false, { currentDate: now })).toBe(
+        "resolved-no",
+      );
+    });
+
+    it("should prioritize resolution over dates", () => {
+      // Even if date is in the future, resolved props show resolution status
+      const futureDate = new Date("2024-06-20T12:00:00Z");
+      expect(getPropStatus(futureDate, true, { currentDate: now })).toBe(
+        "resolved-yes",
+      );
+    });
+  });
+
+  describe("open state", () => {
+    it("should return open when no close date", () => {
+      expect(getPropStatus(null, null, { currentDate: now })).toBe("open");
+    });
+
+    it("should return open when close date is in the future", () => {
+      const futureDate = new Date("2024-06-20T12:00:00Z"); // 5 days away
+      expect(getPropStatus(futureDate, null, { currentDate: now })).toBe(
+        "open",
+      );
+    });
+
+    it("should return open when close date is soon but still in the future", () => {
+      const soonDate = new Date("2024-06-16T10:00:00Z"); // 22 hours away
+      expect(getPropStatus(soonDate, null, { currentDate: now })).toBe("open");
+    });
+  });
+
+  describe("closed state", () => {
+    it("should return closed when past deadline and not resolved", () => {
+      const pastDate = new Date("2024-06-14T12:00:00Z"); // 1 day ago
+      expect(getPropStatus(pastDate, null, { currentDate: now })).toBe(
+        "closed",
+      );
+    });
+
+    it("should return closed when exactly at deadline", () => {
+      expect(getPropStatus(now, null, { currentDate: now })).toBe("closed");
+    });
+  });
+});
+
+describe("getPropStatusFromProp", () => {
+  const now = new Date("2024-06-15T12:00:00Z");
+
+  it("should use prop_forecasts_due_date for private competitions", () => {
+    const prop = {
+      prop_forecasts_due_date: new Date("2024-06-20T12:00:00Z"),
+      competition_forecasts_close_date: new Date("2024-06-10T12:00:00Z"), // past
+      competition_is_private: true,
+      resolution: null,
+    };
+    // Private competition uses prop date (future), not competition date (past)
+    expect(getPropStatusFromProp(prop, { currentDate: now })).toBe("open");
+  });
+
+  it("should use competition_forecasts_close_date for public competitions", () => {
+    const prop = {
+      prop_forecasts_due_date: new Date("2024-06-20T12:00:00Z"), // future
+      competition_forecasts_close_date: new Date("2024-06-10T12:00:00Z"), // past
+      competition_is_private: false,
+      resolution: null,
+    };
+    // Public competition uses competition date (past)
+    expect(getPropStatusFromProp(prop, { currentDate: now })).toBe("closed");
+  });
+
+  it("should handle missing dates gracefully", () => {
+    const prop = {
+      resolution: null,
+    };
+    expect(getPropStatusFromProp(prop, { currentDate: now })).toBe("open");
+  });
+
+  it("should return resolution status regardless of competition type", () => {
+    const prop = {
+      prop_forecasts_due_date: new Date("2024-06-20T12:00:00Z"),
+      competition_is_private: true,
+      resolution: true,
+    };
+    expect(getPropStatusFromProp(prop, { currentDate: now })).toBe(
+      "resolved-yes",
+    );
+  });
+});
+
+describe("getPropStatusLabel", () => {
+  it.each<[PropStatus, string]>([
+    ["open", "Open"],
+    ["closed", "Closed"],
+    ["resolved-yes", "Yes"],
+    ["resolved-no", "No"],
+  ])("should return correct label for %s", (status, expected) => {
+    expect(getPropStatusLabel(status)).toBe(expected);
+  });
+});
diff --git a/lib/prop-status.ts b/lib/prop-status.ts
new file mode 100644
index 0000000..5460745
--- /dev/null
+++ b/lib/prop-status.ts
@@ -0,0 +1,101 @@
+/**
+ * Prop status utilities
+ *
+ * This module provides centralized logic for determining prop lifecycle status
+ * based on deadlines and resolution state.
+ */
+
+export type PropStatus =
+  | "open" // Can still forecast
+  | "closed" // Past deadline, awaiting resolution
+  | "resolved-yes" // Resolved as true
+  | "resolved-no"; // Resolved as false
+
+export interface PropStatusOptions {
+  /** Current date for testing (default: new Date()) */
+  currentDate?: Date;
+}
+
+/**
+ * Get the status of a prop based on its deadline and resolution
+ *
+ * @param closeDate - The deadline for forecasts (forecasts_due_date for private, competition_forecasts_close_date for public)
+ * @param resolution - The resolution value (null if unresolved, true/false if resolved)
+ * @param options - Optional configuration
+ * @returns The prop status
+ *
+ * @example
+ * // Open prop with no deadline
+ * getPropStatus(null, null) // "open"
+ *
+ * // Prop closing in 12 hours
+ * const soon = new Date(Date.now() + 12 * 60 * 60 * 1000);
+ * getPropStatus(soon, null) // "closing-soon"
+ *
+ * // Resolved prop
+ * getPropStatus(pastDate, true) // "resolved-yes"
+ */
+export function getPropStatus(
+  closeDate: Date | null,
+  resolution: boolean | null,
+  options?: PropStatusOptions,
+): PropStatus {
+  const currentDate = options?.currentDate ?? new Date();
+
+  // Check resolution first - resolved props have a definitive status regardless of dates
+  if (resolution !== null) {
+    return resolution ? "resolved-yes" : "resolved-no";
+  }
+
+  // No deadline means always open
+  if (closeDate === null) {
+    return "open";
+  }
+
+  const timeUntilClose = closeDate.getTime() - currentDate.getTime();
+
+  // Past deadline
+  if (timeUntilClose <= 0) {
+    return "closed";
+  }
+
+  return "open";
+}
+
+/**
+ * Helper to get prop status from a VProp-like object
+ * Automatically determines the correct close date based on competition type
+ */
+export function getPropStatusFromProp(
+  prop: {
+    prop_forecasts_due_date?: Date | null;
+    competition_forecasts_close_date?: Date | null;
+    competition_is_private?: boolean | null;
+    resolution: boolean | null;
+  },
+  options?: PropStatusOptions,
+): PropStatus {
+  // For private competitions, use prop-level deadline
+  // For public competitions, use competition-level deadline
+  const closeDate = prop.competition_is_private
+    ? (prop.prop_forecasts_due_date ?? null)
+    : (prop.competition_forecasts_close_date ?? null);
+
+  return getPropStatus(closeDate, prop.resolution, options);
+}
+
+/**
+ * Get human-readable label for a prop status
+ */
+export function getPropStatusLabel(status: PropStatus): string {
+  switch (status) {
+    case "open":
+      return "Open";
+    case "closed":
+      return "Closed";
+    case "resolved-yes":
+      return "Yes";
+    case "resolved-no":
+      return "No";
+  }
+}