The Coast Guard has published Marine Safety Information Bulletin 11-20 (MSIB 11-20) to provide further clarification when determining which Marine Transportation System (MTS) workers are considered essential in regions affected by the coronavirus quarantine and shelter-in-place orders.The uninterrupted flow of commerce is critical to both national security and economic vitality. During the ongoing national emergency, it is paramount that we safeguard the continued operation of the MTS in the face of the acute and evolving threats posed by the Covid-19 pandemic, according to MSIB 11-20. The MTS, which provides more than 90% of the domestic supply chain, is dependent on an extensive support network made up of workers from both the private and public sectors.

This MSIB should be used to provide further clarification when making determinations regarding which MTS workers are considered essential in regions impacted by Covid-19 quarantine and shelter-in-place orders.

Though not meant to be an exhaustive list, the following personnel are essential for sustaining the continuous flow of maritime commerce:

  • Merchant mariners;
  • Federal and state pilots;
  • Stevedores, longshoremen, and line handlers;
  • Representatives of seafarers’ welfare and labor organizations;
  • Marine consultants, naval architects, marine exchanges, surveyors and shipyard workers;
  • Classification society and recognized organization surveyors and auditors;
  • Vessel owners, operators, shipping agents and marine dispatchers;
  • Technical representatives and contractors;
  • Bridge operators and bridge repair personnel;
  • Lock and dam operators and workers;
  • Lighthouse servicing and repair personnel;
  • Commercial barge fleeting facility personnel;
  • Equipment, cargo, crane and dredging operators;
  • Truck drivers, launch/tug/towing operators and other intermodal transportation workers;
  • Vendors and ship chandlers providing ship services, husbandry and provisions;
  • Federal and state agency personnel (e.g., Coast Guard, Customs and Border Protection, Centers for Disease Control and Prevention, Army Corps of Engineers, local health and safety organizations)


In addition to the examples above, this MSIB has some select sections from the Cybersecurity and Infrastructure Security Agency (CISA) guidance memo (see below). Though not exhaustive these are examples of where essential MTS workers may be found in the memo. Information in bold has been added by the Coast Guard to this MSIB for further clarification.


  • Employees supporting or enabling transportation functions, including truck drivers, bus drivers, dispatchers, maintenance and repair technicians, warehouse workers, truck stop and rest area workers, and workers that maintain and inspect infrastructure (including those that require cross-jurisdiction travel)
  • Maritime transportation workers – port workers, mariners, equipment operators – To clarify this includes port and facility security personnel and other port authority and commercial facility personnel.
  • Employees who repair and maintain vehicles, aircraft, rail equipment, marine vessels, and the equipment and infrastructure that enables operations that encompass movement of cargo and passengers
  • Employees supporting or enabling transportation functions, including dispatchers, maintenance and repair technicians, warehouse workers, truck stop and rest area workers, and workers that maintain and inspecting infrastructure (including those that require cross-border travel)



  • Petroleum product storage, pipeline, marine transport, terminals, rail transport, road transport
  • Crude oil storage facilities, pipeline, and marine transport
  • Petroleum refinery facilities
  • Retail fuel centers such as gas stations and truck stops, and the distribution systems that support them



  • Workers who support hazardous materials response and cleanup – To clarify this includes Oil Spill Removal Organizations and salvage and marine firefighting response companies. Additionally, this includes response and cleanup of petroleum products.



  • Workers necessary for the manufacturing of materials and products needed for medical supply chains, and for supply chains associated with transportation, energy, communications, food and agriculture, chemical manufacturing, nuclear facilities, the operation of dams, water and wastewater treatment, emergency services, and the defense industrial base. Additionally, workers needed to maintain the continuity of these manufacturing functions and associated supply chains.



Workers performing security, incident management, and emergency operations functions at or on behalf of healthcare entities including healthcare coalitions, who cannot practically work remotely – To clarify this includes maritime specific medical providers who meet shipboard medical needs for maritime crews.

Many MTS workers have a federal Transportation Worker Identification Card (TWIC) that may be used to confirm their MTS nexus. However, many others in the support framework will not have specific maritime identification or may be in the process of applying for a TWIC card. In any cases where there is a question, state officials are highly encouraged to ask their local Coast Guard Captain of the Port to confirm whether the worker is essential to MTS operations.

Questions about this bulletin should be directed to [email protected]