Harbor Maintenance Tax (HMT)
The Harbor Maintenance Tax is a 0.125% excise tax on the value of commercial cargo loaded or unloaded at U.S. ports — paid by importers, exporters, and domestic shippers. It is collected by U.S. Customs and Border Protection and deposited into the Harbor Maintenance Trust Fund (HMTF), which Congress appropriates to the Army Corps of Engineers to dredge and maintain commercial navigation channels at U.S. ports. For the broader framework governing maritime commerce, see merchant marine and maritime law and ocean shipping reform. If your company imports $10 million in goods through a U.S. seaport, you owe $12,500 in HMT. A separate per-passenger excise ($3/passenger) applies to certain commercial ocean voyages. The HMT generates roughly $2 billion per year and has been a persistent source of trade policy controversy — particularly because Congress for years appropriated far less than the fund collected, running up a surplus that exporters and importers argued represented an unconstitutional export tax.
Current Law (2026)
| Parameter | Value |
|---|---|
| Governing statute | 26 U.S.C. §§ 4461–4462 (cargo); §§ 4471–4472 (passengers) |
| HMT rate | 0.125% of cargo value (commercial cargo loaded or unloaded at a U.S. port) |
| Passenger vessel tax | $3.00 per passenger on covered voyages |
| Collection agency | U.S. Customs and Border Protection (CBP) |
| Revenue destination | Harbor Maintenance Trust Fund (HMTF) |
| Spending authority | Army Corps of Engineers, for harbor dredging and maintenance |
| Export exemption | Exports are explicitly exempt from HMT (§ 4462(a)(4)) — a constitutional requirement |
| Inland waterway distinction | HMT applies at ports; a separate Inland Waterways Trust Fund (fuels tax) covers rivers and canals |
| Covered voyages | Commercial passenger vessels extending over 1+ nights; vessels transporting passengers between U.S. ports and foreign ports |
Legal Authority
- 26 U.S.C. § 4461 — Imposition of HMT: tax imposed on "port use," which is loading or unloading of commercial cargo at a U.S. port; rate is 0.125% of cargo value; the person using the port is the taxpayer
- 26 U.S.C. § 4462 — Definitions and special rules: "port use" means commercial cargo loading/unloading at a channel or harbor maintained by the U.S.; "commercial cargo" includes any cargo transported for compensation; specific exemptions for exports, certain bulk cargo, fishing vessels, and federal government cargo; "United States" includes the 50 states, DC, Puerto Rico, and U.S. possessions
- 26 U.S.C. § 4471 — Passenger vessel tax: $3 per passenger on a covered voyage; paid by the vessel operator; applies to commercial voyages of 1+ nights between U.S. and foreign ports, or voyages originating and ending in the U.S. with a stop in a foreign port (cruise ships)
- 26 U.S.C. § 4472 — Covered voyage definitions: "covered voyage" includes a commercial passenger vessel of 1+ nights or a commercial vessel transporting passengers between U.S. and adjacent foreign ports; exemptions for vessels with 17 or fewer passengers
The Harbor Maintenance Trust Fund
HMT revenue flows into the Harbor Maintenance Trust Fund, a dedicated Treasury account. Congress must appropriate money from the HMTF to the Army Corps of Engineers for specific harbor maintenance and dredging projects — the tax revenue alone doesn't automatically fund the work.
For many years, Congress appropriated less than the HMTF collected — the fund accumulated a surplus exceeding $9 billion at its peak. Critics argued this was effectively a hidden import tax being used for general deficit reduction rather than its stated purpose. The Water Resources Reform and Development Act of 2014 (WRRDA) and the Water Infrastructure Improvements for the Nation Act of 2016 (WIIN) required that HMT collections be fully spent on harbor maintenance — eliminating the surplus accumulation practice and ensuring the tax revenues are actually used for their designated purpose.
The Export Exemption and Constitutional Limits
The original 1986 HMT applied to both imports and exports. In 1998, the Supreme Court ruled in United States v. United States Shoe Corp. that the HMT as applied to exports was an unconstitutional tax on exports, prohibited by the Export Clause of the U.S. Constitution (Art. I, § 9, cl. 5). Congress subsequently exempted exports from the HMT (§ 4462(a)(4)).
This means the HMT applies only to imports and domestic (coastwise) cargo movements — it is explicitly not imposed on the export side of trade.
Cruise Ship Tax
The $3/passenger tax under § 4471 applies to cruise ships — technically "covered voyages" on "commercial passenger vessels extending over 1 or more nights." This is a flat per-person amount, not a percentage, and is paid by the vessel operator rather than the passenger directly. Cruise lines typically factor it into ticket pricing. Revenue from the passenger vessel tax is modest compared to the cargo HMT.
How It Affects You
<!-- pria:personalize type="impact" -->If you import goods by ocean freight: HMT is assessed on the dutiable value of your cargo at the port of entry. For a typical container load of consumer goods worth $100,000, HMT is $125. You pay it as part of your CBP entry filing — it appears on your customs entry and is collected by CBP alongside import duties. HMT does not apply to air freight, truck imports at land borders, or rail imports.
If you export goods: Your exports are exempt from HMT under the Export Clause ruling. However, carriers and terminal operators may impose their own port fees separately from the statutory HMT — these private fees are not the same as the federal tax and are not exempt simply because you are exporting.
If you ship coastwise (domestic ocean cargo): Domestic cargo moved between U.S. ports — such as goods shipped from the Pacific Northwest to Hawaii or from Gulf Coast refineries to East Coast terminals — is subject to HMT on both the loading and unloading legs.
If you operate a cruise line or book a cruise: The $3/passenger tax is embedded in cruise pricing. It is a de minimis charge relative to cruise ticket prices, but it applies globally to any cruise with U.S. port calls that constitutes a "covered voyage" under § 4472.
If you are a port authority or maritime industry stakeholder: HMTF spending decisions by Congress and the Army Corps of Engineers directly affect navigation channel depths, dredging cycles, and port competitiveness. The shift to full appropriation of HMT collections means more predictable funding for harbor maintenance projects.
<!-- /pria:personalize -->State Variations
States and port authorities may impose their own port fees, terminal fees, and wharfage charges separately from the federal HMT. California, New York/New Jersey, and Texas ports have their own fee structures layered on top of federal charges.
Pending Legislation
No major pending changes to the HMT rate or structure as of April 2026. Water Resources Development Act (WRDA) legislation, which Congress typically passes every two years, authorizes Army Corps projects funded by HMTF but does not change the underlying tax.
Recent Developments
- WRDA 2022 authorized major harbor deepening projects: The Water Resources Development Act of 2022 authorized the Army Corps of Engineers to deepen and widen channels at multiple large container ports, including projects at the Port of New York/New Jersey, Savannah, Baltimore, and Gulf Coast facilities. These projects are funded through HMTF appropriations. With post-pandemic container port congestion exposing depth limitations at major East Coast ports, WRDA 2022 prioritized projects that would allow fully-laden Neopanamax container ships (which draw over 50 feet) to call at more U.S. ports. Congress must still appropriate HMTF funds separately for each project — authorization doesn't guarantee spending.
- HMTF surplus largely eliminated — full appropriation now the norm: After years of accumulating a surplus exceeding $9 billion (with HMT collections outpacing Army Corps appropriations), the WIIN Act of 2016 and subsequent appropriations commitments have largely closed the gap. HMTF appropriations have generally matched or approached annual HMT collections of approximately $2 billion since 2020. Port authorities and the maritime industry had long argued the surplus represented an implicit import tax used for general deficit reduction rather than harbor maintenance — that argument lost most of its force once Congress committed to full appropriation.
- Tariff-driven cargo shifts create HMT revenue uncertainty: The 2025 tariff escalation — including broad tariff increases on Chinese goods and new tariffs on steel, aluminum, and other products — reduced U.S. import volumes on affected goods, which in turn reduces HMT collections. Lower import volumes mean lower HMT revenue, potentially tightening HMTF funds available for Army Corps projects. Port authorities that had planned capital investment based on sustained HMT funding levels are tracking the revenue effect of the tariff regime on HMTF projections. The 0.125% rate has not changed; it's the cargo value base that shifts with trade flows.
- No major HMT rate changes pending: The HMT rate of 0.125% has been unchanged since 1986. Periodic proposals to increase the rate (to generate more HMTF funding for backlogged dredging projects) or to eliminate the export exemption controversy through structural changes have not advanced in the 119th Congress. Water Resources Development Act legislation, which Congress typically considers every two years, focuses on project authorization rather than the underlying tax structure.