The short version
- 42 CFR 71.21(a) requires an immediate report to the quarantine station at or nearest the arrival port, before arrival.
- It covers crew as well as passengers, and reaches people who have already disembarked or been removed.
- Ill person is defined at 42 CFR 71.1 and is conjunctive: fever plus one of seven signs, or fever persisting over 48 hours.
- The vessel sign list differs from the aircraft list in four rows out of nine.
- Ships with 13 or more passengers carry separate 24 hour and 4 hour gastroenteritis clocks.
The duty is immediate, and it reaches back fifteen days
A master bound for a United States port carries a federal reporting obligation that most operators discover only when a quarantine officer asks why it was not met.
42 CFR 71.21(a) requires the master of a ship destined for a US port to report immediately to the quarantine station at or nearest the port of arrival the occurrence on board of any death, or any ill person, among passengers or crew.[1]
Three parts of that sentence are routinely misread.
| Phrase | Common reading | What it actually says |
|---|---|---|
| Immediately | On arrival, with the other paperwork | Before arrival, as soon as the death or illness occurs[1] |
| Passengers or crew | Passengers only, so cargo vessels are exempt | Crew are named explicitly. A cargo vessel with no passengers is fully in scope[1] |
| On board | Anyone still aboard at arrival | Including those who have disembarked or have been removed. Landing the casualty does not end the duty[1] |
The lookback is the fifteen day period preceding the date of expected arrival, or the period since departure from a US port, whichever is shorter.[1] A vessel eleven days out from a foreign port carries an eleven day window. A vessel that sailed from Seattle four days ago carries a four day window.
The obligation sits alongside the medical duties an operator already knows. A compliance audit checks the chest and the records. It does not usually check whether the bridge can apply a federal clinical definition, and the owner and DPA split rarely assigns it to anyone.
Google is answering this with an archive and a mirror
A live capture of page one in September 2026 is worth reading closely, because the pattern is unusual even by the standards of this topic.
The Centers for Disease Control page that governs this question does rank, but not from cdc.gov. It is served through a third party mirror site. Two more results come from a university web archive of dead CDC pages last updated in 2013. Two are Department of Health and Human Services guidance portal stubs. The top Coast Guard result is a COVID era marine safety bulletin from 2020.
So an operator asking a live 2026 compliance question is served a thirteen year old archived page, a pandemic bulletin, and a mirror. The regulation itself ranks, as raw text, with no operator translation. The pattern is identical to the 21 CFR 1301.25 page, where the statute ranked and nothing explained it.
That is the same defect shape recorded across this site: a withdrawn ILO instrument still ranking for chest contents, the wrong subchapter ranking first for uninspected vessels, and UK certificates answering a US fishing question.
Ill person is a two limb test, and fever alone does not meet it
The whole obligation turns on one defined term, and the definition sits in a different section of the same part. 42 CFR 71.1 defines ill person, and for a vessel it is a conjunctive test.[2]
The vessel definition, verbatim structure
An ill person on a vessel is one who (A) has a fever, meaning a measured temperature of 100.4 degrees Fahrenheit or 38 Celsius or greater, or feels warm to the touch, or gives a history of feeling feverish, accompanied by one or more of seven listed signs; or (B) has a fever that has persisted for more than 48 hours; or (C) has acute gastroenteritis; or (D) has symptoms or other indications of communicable disease as the Director may announce in the Federal Register.[2]
Limb (A) is the one that catches people. A fever on its own is not a reportable illness under limb (A). It becomes reportable only when accompanied by one of the seven signs, or when it crosses the 48 hour mark under limb (B).
Report only on fever and you over-report. Wait for something dramatic and you miss a reportable case on day one. The consequence lands on the same people who run voyages far from definitive care and on whoever holds the crew medical file. This is the same half-a-test problem we documented in the injury reporting threshold.
The vessel list is not the aircraft list
Section 71.1 defines ill person separately for aircraft and for vessels, and the two lists of accompanying signs are different. No guidance page we found says so.[2]
| Accompanying sign | Aircraft | Vessel |
|---|---|---|
| Skin rash | Yes | Yes |
| Difficulty breathing | Yes | Yes, or suspected or confirmed pneumonia |
| Persistent cough | Yes | Yes, or cough with bloody sputum |
| Decreased consciousness or confusion of recent onset | Yes | Yes |
| New unexplained bruising or bleeding without previous injury | Yes | Yes |
| Persistent vomiting | Yes, other than air sickness | Yes, other than sea sickness |
| Headache with stiff neck | Yes | Yes |
| Persistent diarrhea | Yes | Not listed |
| Appears obviously unwell | Yes | Not listed |
Two signs on the aircraft list are absent from the vessel list, and two entries on the vessel list are broader than their aircraft equivalents.[2] A vessel checklist copied from an aviation template is wrong in four rows out of nine.
The same copying error appears elsewhere on this site. Kit requirements by vessel class and the Subchapter L review both document rules imported from the wrong instrument.
Building the correct checklist, and the crew training that goes with it, is a documentation exercise rather than a clinical one. That is what our maritime medical consulting engagement produces.
The thirteen passenger rule has its own two clocks
Paragraph (c) runs a separate regime for vessels carrying thirteen or more passengers, and it is the only part of 71.21 with fixed hours attached.[1]
Three deadlines, two of them numeric
Cases of acute gastroenteritis on a ship carrying 13 or more passengers are reported 24 hours before arrival. Any additional cases arising after that report go in within 4 hours of arrival.[1] The general duty in paragraph (a), any death or ill person, is immediate and carries no passenger threshold at all.[1]
Note the asymmetry. The gastroenteritis rule has numbers and a passenger threshold. The general rule has neither, which is why operators of workboats and cargo vessels assume it does not reach them. It does. See how the 13 passenger line works elsewhere in US law and the Subchapter M position.
Three separate reporting channels, one incident
A death on board can trigger three federal reports to three different agencies, and satisfying one does not satisfy the others.
| Channel | Instrument | Goes to |
|---|---|---|
| Quarantine | 42 CFR 71.21[1] | The quarantine station at or nearest the arrival port, immediately |
| Marine casualty | 46 CFR part 4[3] | The Coast Guard, on the casualty timetable |
| Controlled substances | 21 CFR 1301.25[4] | Accounting duties if scheduled drugs were dispensed |
Our walkthrough of death on board covers the Coast Guard and consular side in full. This article is the quarantine channel, which that one does not open. If controlled substances were given, the recordkeeping article and the two annual reports carry the accounting. Where the vessel holds a hospital space under 46 CFR 92.20-35 or 108.209, the isolation question arrives with it.
Free pratique is downstream of this
Reporting under 71.21 feeds the arrival process. 42 CFR 71.33 governs persons held in quarantine, and a vessel that failed to report an ill person is starting that conversation from the wrong place.[5] The cost of a delayed berth almost always exceeds the cost of reporting.
What a defensible reporting programme looks like
The regulation names the master. It says nothing about how the master decides, records or transmits, which is where the programme has to do the work.
- Put the vessel definition of ill person on the bridge, not the aircraft one, with all seven accompanying signs printed.[2]
- Log temperature with a number. The definition accepts feels warm to the touch and a history of feeling feverish, but 100.4 degrees Fahrenheit is the only defensible entry.[2]
- Start a 48 hour clock on every fever, because limb (B) triggers with no other sign at all.[2]
- Identify the quarantine station for each port on the schedule before sailing. The duty is to the station at or nearest the arrival port, and finding it under pressure is not a plan.[1]
- Keep the duty alive after a medevac. The text covers those who have disembarked or been removed.[1]
- Run the 24 hour and 4 hour gastroenteritis clocks separately if you carry 13 or more passengers.[1]
- Record the decision not to report with the reason. An unreported case with a reasoned log entry is a defensible position. An unreported case with no entry is not.
Deciding whether a case meets a federal clinical definition, at 0300, from a satellite call, is not a job for a master alone. The medevac decision has the same shape and the same answer: a physician on the other end of the line.
Discovery Health MD is led by Ann Jarris MD, MBA, FACEP, a board certified emergency physician. We build the checklist, train the crew to it and take the call. If the chest is part of the same programme, ship medical chest management covers it, and the six decisions sets the frame. Operators changing flag state should note that 42 CFR 71.21 attaches to the US port call, not to the flag, so it survives the transfer unchanged. Speak to the team.
Common questions
When must a ship report an illness to CDC?
Immediately, under 42 CFR 71.21(a). The master of a ship destined for a US port must report to the quarantine station at or nearest the port of arrival the occurrence on board of any death or any ill person among passengers or crew, including those who have disembarked or have been removed[1]. The lookback is the 15-day period preceding expected arrival, or the period since departure from a US port, whichever is shorter[1]. It is a before-arrival duty, not an arrival formality. Our consulting service builds the procedure.
Does a fever alone have to be reported?
Not under limb (A). The vessel definition of ill person in 42 CFR 71.1 requires a fever of 100.4 degrees Fahrenheit or 38 Celsius or greater, or feeling warm to the touch, or a history of feeling feverish, ACCOMPANIED BY one or more of seven listed signs[2]. A fever with none of those signs becomes reportable only under limb (B), when it has persisted for more than 48 hours[2]. That is why every fever needs a 48-hour clock started against it.
Does 42 CFR 71.21 apply to cargo vessels with no passengers?
Yes. Paragraph (a) names any death or ill person among passengers OR CREW and sets no passenger threshold[1]. The 13-passenger threshold in paragraph (c) applies only to the separate acute gastroenteritis regime, with its 24-hour before arrival and 4-hour after arrival deadlines[1]. Operators of cargo vessels and workboats routinely assume the general duty is a cruise-ship rule. It is not. Read the towing vessel analysis for the same pattern.
Is the ill person definition the same for ships and aircraft?
No, and the difference is checkable. 42 CFR 71.1 lists the accompanying signs separately[2]. The aircraft list includes persistent diarrhea and appears obviously unwell; the vessel list contains neither. The vessel list is broader in two places, covering difficulty breathing or suspected or confirmed pneumonia, and persistent cough or cough with bloody sputum[2]. A vessel checklist copied from an aviation template is wrong in four rows out of nine.
Does reporting to the Coast Guard satisfy the CDC requirement?
No. They are separate channels under separate instruments. 42 CFR 71.21 runs to the quarantine station at or nearest the arrival port[1], while marine casualty reporting runs to the Coast Guard under 46 CFR part 4[3]. If controlled substances were dispensed, 21 CFR 1301.25 adds accounting duties on top[4]. One incident can owe three federal reports. Our death on board walkthrough covers the Coast Guard and consular side.
Does the duty end once the sick crew member is landed?
No. The text of 42 CFR 71.21(a) expressly covers those who have disembarked or have been removed[1]. A medevac ashore, a repatriation, or a transfer to a shoreside hospital does not end the reporting obligation for the vessel. The 15-day lookback continues to reach the case. See our analysis of when to evacuate or disembark a seafarer for the decision that precedes it.
What temperature counts as a fever under the rule?
A measured temperature of 100.4 degrees Fahrenheit, or 38 degrees Celsius, or greater[2]. The definition also accepts feels warm to the touch and a history of feeling feverish, so a case can qualify without a thermometer[2]. For a defensible log entry, record the measured number. A subjective entry is compliant but weak evidence if the decision is ever reviewed. Our maritime medical consulting line writes the log standard.
