Importers of HS 9018.39 (other) from Mexico actually paid 9.99% on the taxed portion of the value in 2026-06 — 0.95% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is Free. Over the window the rate on the taxed portion moved null% → 9.99%, with the largest single step +23.2pp in 2025-03. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is Free — importers actually paid 9.99%, so the trade-war overlay added 10 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "9018.39", origin: "Mexico") · see it at trimtabist.com/tariffs
HS 9018.39. The schedule base rate is Free; importers from Mexico actually paid 9.99% on the dutiable value in 2026-06 — the trade-war overlay added 10 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved % (2023-07) → 9.99% (2026-06), largest single step +23.2pp in 2025-03.
Mexico's lower duty (0.95% vs 5.71%) lets it price up to 4.7% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, China actually lands cheaper — $8.78/kg vs $36.31/kg (duty in, freight out).
5 Chapter-99 measures name Mexico; scope mapping is partial (several annexes are PDFs) — absence never means exemption. They do not sum, and some are product-specific — the collected rate above is the composed truth.
All goods from Mexico · the whole tariff ledger · 6 CBP rulings cite this code · reproduce: tariff_story(hs: "9018.39", origin: "Mexico") via /connect. Not customs or legal advice.