diff --git a/scripts/patch_main_coupon_blocks.py b/scripts/patch_main_coupon_blocks.py
new file mode 100644
index 0000000..1d809ca
--- /dev/null
+++ b/scripts/patch_main_coupon_blocks.py
@@ -0,0 +1,132 @@
+#!/usr/bin/env python3
+"""Patch the two main trucking source campaigns (MCS-150 #186, Inactive USDOT
+#188) coupon blocks to use the build step's on-the-fly computed prices
+(coupon_price_full / coupon_price_deal) instead of the hardcoded "$79 $47" /
+"$149 $89", which were only true at 40% off and would be false on the 20/30%
+A/B arms.
+
+Idempotent: re-running replaces the coupon if-block again with the same content.
+Run inside the workers container on prod:
+    python3 scripts/patch_main_coupon_blocks.py [--dry-run]
+"""
+from __future__ import annotations
+
+import argparse
+import os
+import re
+import sys
+
+ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+if ROOT not in sys.path:
+    sys.path.insert(0, ROOT)
+
+from scripts import build_trucking_campaigns as b  # reuse lm_api + auth
+
+
+def _deal_block(service_phrase: str, extra_expiry_line: str = "") -> str:
+    """Coupon-aware offer block matching the deficiency _deal_box structure:
+    real was/now prices when priceable, percent-only otherwise."""
+    priced = (
+        '<p style="font-size:18px;font-weight:700;color:#9a3412;margin:0 0 4px">'
+        f'{service_phrase} for '
+        '<span style="text-decoration:line-through;color:#c2410c;font-weight:600">'
+        '{{ .Subscriber.Attribs.coupon_price_full }}</span> '
+        '<span style="color:#15803d">{{ .Subscriber.Attribs.coupon_price_deal }}</span>.</p>'
+    )
+    unpriced = (
+        '<p style="font-size:18px;font-weight:700;color:#9a3412;margin:0 0 4px">'
+        f'{service_phrase}.</p>'
+    )
+    expiry = "Expires {{ .Subscriber.Attribs.coupon_expires }}."
+    if extra_expiry_line:
+        expiry += " " + extra_expiry_line
+    return (
+        '{{ if .Subscriber.Attribs.coupon_code }}\n'
+        '<div style="background:#fff7ed;border:2px solid #f97316;border-radius:10px;'
+        'padding:20px;margin:20px 0;text-align:center">\n'
+        '<p style="font-size:13px;font-weight:700;color:#9a3412;letter-spacing:.04em;'
+        'margin:0 0 6px">TODAY ONLY - {{ .Subscriber.Attribs.coupon_pct }}% OFF OUR SERVICE FEE</p>\n'
+        '{{ if .Subscriber.Attribs.coupon_priceable }}' + priced + '{{ else }}' + unpriced + '{{ end }}\n'
+        '<p style="font-size:14px;color:#9a3412;margin:0 0 4px">Use code '
+        '<strong style="font-size:16px;letter-spacing:.08em">{{ .Subscriber.Attribs.coupon_code }}</strong> '
+        '(already applied when you click below).</p>\n'
+        f'<p style="font-size:12px;color:#b91c1c;font-weight:700;margin:0">{expiry}</p>\n'
+        '</div>\n'
+    )
+
+
+# Per-campaign: the new coupon if-block (deal branch + original else branch).
+BLOCKS = {
+    186: (
+        _deal_block("We file your MCS-150 update")
+        + '{{ else }}\n'
+        '<div style="background:#f0fdf4;border:2px solid #86efac;border-radius:10px;'
+        'padding:20px;margin:20px 0;text-align:center">\n'
+        '<p style="font-size:18px;font-weight:700;color:#166534;margin:0 0 4px">'
+        'We can file your MCS-150 update for you.</p>\n'
+        '<p style="font-size:14px;color:#15803d;margin:0">No Login.gov needed. '
+        'No government portals. We handle everything.</p>\n'
+        '</div>\n'
+        '{{ end }}'
+    ),
+    188: (
+        _deal_block("Reactivate your USDOT", "Reactivation takes as few as 5 business days.")
+        + '{{ else }}\n'
+        '<div style="background:#f0fdf4;border:2px solid #86efac;border-radius:10px;'
+        'padding:20px;margin:20px 0;text-align:center">\n'
+        '<p style="font-size:18px;font-weight:700;color:#166534;margin:0 0 4px">'
+        'Reactivation takes as few as 5 business days.</p>\n'
+        '<p style="font-size:14px;color:#15803d;margin:0">We file electronically with '
+        'FMCSA - no Login.gov account needed.</p>\n'
+        '</div>\n'
+        '{{ end }}'
+    ),
+}
+
+_BLOCK_RE = re.compile(
+    r"\{\{\s*if\s+\.Subscriber\.Attribs\.coupon_code\s*\}\}.*?\{\{\s*end\s*\}\}",
+    re.DOTALL,
+)
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--dry-run", action="store_true")
+    args = ap.parse_args()
+
+    for cid, new_block in BLOCKS.items():
+        camp = b.get_base_campaign(cid)
+        body = camp.get("body") or ""
+        matches = _BLOCK_RE.findall(body)
+        if len(matches) != 1:
+            print(f"  [#{cid}] SKIP: found {len(matches)} coupon if-blocks (expected 1)")
+            continue
+        new_body, n = _BLOCK_RE.subn(new_block, body)
+        if "$47" in new_block or "$89" in new_block or "$79" in new_block or "$149" in new_block:
+            print(f"  [#{cid}] ABORT: new block still contains a hardcoded price")
+            continue
+        # Sanity: no hardcoded coupon price survives in the rewritten coupon area.
+        if args.dry_run:
+            print(f"  [#{cid}] DRY-RUN would update body ({len(body)} -> {len(new_body)} chars)")
+            continue
+        payload = {
+            "name": camp.get("name"),
+            "subject": camp.get("subject"),
+            "lists": [l["id"] for l in camp.get("lists", []) if isinstance(l, dict)] or [8],
+            "from_email": camp.get("from_email"),
+            "type": camp.get("type") or "regular",
+            "content_type": camp.get("content_type") or "html",
+            "body": new_body,
+            "altbody": camp.get("altbody"),
+            "template_id": camp.get("template_id") or 6,
+            "tags": camp.get("tags") or [],
+            "messenger": camp.get("messenger") or "email",
+            "headers": camp.get("headers") or [],
+        }
+        b.lm_api(f"/campaigns/{cid}", payload, "PUT")
+        print(f"  [#{cid}] updated coupon block (body {len(body)} -> {len(new_body)} chars)")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())