Before the NMC will issue your Merchant Mariner Credential, you must pass a physical exam on Form CG-719K and a DOT-compliant 5-panel drug test. This guide covers every standard, substance tested, who administers the exams, how long results stay valid, and what happens if you fail.
CG-719K
Physical exam form
5-Panel
DOT urine drug test
185 days
Drug test validity
12 months
Physical validity
The CG-719K is the standard USCG medical exam form required for all original and renewal MMC applications. It documents your fitness for duty across vision, hearing, cardiovascular health, and general medical status.
The USCG does not require a "USCG-designated physician." Any licensed U.S. medical provider in the following categories can sign the CG-719K:
MD -- Medical Doctor
Your primary care physician, a clinic doctor, or an occupational medicine physician. Most direct route for most applicants.
DO -- Doctor of Osteopathy
Equivalent to an MD for USCG purposes. Full prescribing authority and qualified to sign the form.
NP -- Nurse Practitioner
Nurse Practitioners with independent practice authority can sign the CG-719K. Common at urgent care and occupational health clinics.
PA -- Physician Assistant
Physician Assistants practicing under physician supervision can sign the CG-719K. Also widely available at occupational health clinics.
Cannot sign the CG-719K:
Chiropractors, naturopaths, acupuncturists, optometrists (for the full physical -- only for vision testing), and any non-licensed or non-credentialed provider. The NMC will reject an improperly certified form.
Typical cost: $100 to $300 depending on provider and location. Occupational health clinics often offer competitive pricing for DOT/maritime physicals.
| Test | Minimum Standard | Correction Allowed | Corrected Standard |
|---|---|---|---|
| Distant visual acuity | 20/200 or better in each eye | Yes -- glasses or contacts permitted | 20/40 or better in better eye; 20/80 or better in other eye |
| Color vision | Must distinguish red and green navigation light colors | Alternative tests permitted if Ishihara fails | Farnsworth D-15 or City University test; or restriction notation |
| Hearing | Forced whisper at 3 meters in better ear | Hearing aids may be permitted with physician evaluation | Physician discretion; must hear warning signals and crew communications |
| Blood pressure | Below 160/100 mmHg | Controlled hypertension acceptable with medication | Medication and condition noted on CG-719K; physician certifies fitness |
Distant Visual Acuity
Each eye must have uncorrected vision of at least 20/200. With correction (glasses or contacts), the better eye must be 20/40 or better, and the other eye must be 20/80 or better. You may wear corrective lenses while operating the vessel -- that is the whole point of the standard. The uncorrected threshold of 20/200 ensures you have enough residual vision to function if corrective lenses are lost or broken at sea.
Color Vision -- Red and Green
Color vision testing is required because mariners must distinguish the red (port) and green (starboard) running lights of other vessels, which is fundamental to collision avoidance under the COLREGS. The standard test is the Ishihara pseudoisochromatic plate test. If you fail the Ishihara plates, you have options before being restricted:
Hearing Standard
You must be able to hear a forced whisper in your better ear at a distance of approximately 3 meters (about 10 feet) in a quiet room. This simulates the ability to hear crew communications and auditory warning signals aboard a vessel. Hearing aids may be permitted at the examining physician's discretion with appropriate documentation.
Blood Pressure Limits
Blood pressure must be below 160/100 mmHg at the time of examination. Controlled hypertension -- meaning high blood pressure managed by medication to within the acceptable range -- is generally acceptable. The examining physician must note the condition and all medications on the CG-719K form. Uncontrolled hypertension will require further evaluation and may require a waiver from the NMC.
Physical Exam Validity Period
The CG-719K is valid for 12 months from the date of examination. The NMC must receive your application within that window. If the physical expires before you submit, you must redo the examination. For renewal applications, a new physical is always required regardless of when your previous exam was performed.
The drug test is a separate requirement from the physical exam. It is a federally regulated DOT urine drug test, not a general physician-ordered test. The USCG operates under DOT drug testing regulations in 49 CFR Part 40 and 46 CFR Part 16.
The drug test must be collected at a DOT-certified collection site and analyzed by a SAMHSA-certified laboratory. The process involves a chain of custody from collection through laboratory analysis through MRO review.
Collection Site
DOT-certified or SAMHSA-certified collection site. Quest Diagnostics, LabCorp, and many occupational health clinics are certified. A general doctor's office is not sufficient unless it is also a certified DOT collection site.
Laboratory
The specimen must be analyzed by a SAMHSA-certified laboratory. Collection sites that are not full laboratories will ship the specimen to a certified lab. The chain of custody form tracks the specimen from collection through analysis.
MRO Review
A Medical Review Officer -- a licensed physician certified in DOT drug testing -- reviews all results before they are finalized. The MRO contacts donors with positive results to ask about legitimate medical explanations before reporting the result.
The standard DOT test panel screens for five substance categories. Detection windows are averages -- individual results vary based on metabolism, body composition, hydration, and frequency of use.
Marijuana (THC)
Window: 3-30 days (casual to chronic use)Metabolite tested: THC-COOH
Cutoff levels: 50 ng/mL screen / 15 ng/mL confirm
State-legal status irrelevant under federal maritime law. Medical marijuana cards are not a valid defense.
Cocaine
Window: 2-4 daysMetabolite tested: Benzoylecgonine
Cutoff levels: 150 ng/mL screen / 100 ng/mL confirm
Includes crack cocaine and powder cocaine. Detection window is relatively short.
Amphetamines
Window: 2-4 daysMetabolite tested: Amphetamine / Methamphetamine
Cutoff levels: 500 ng/mL screen / 250 ng/mL confirm
Includes methamphetamine, MDMA (ecstasy). Legitimate Adderall prescriptions must be disclosed to MRO.
Opiates
Window: 2-4 daysMetabolite tested: Codeine / Morphine / Heroin (6-MAM)
Cutoff levels: 2000 ng/mL screen / 2000 ng/mL confirm
Heroin uniquely identified via 6-MAM metabolite. Legitimate opiate prescriptions must be disclosed to MRO.
Phencyclidine (PCP)
Window: 3-8 daysMetabolite tested: Phencyclidine
Cutoff levels: 25 ng/mL screen / 25 ng/mL confirm
Rarely prescribed legitimately. One of the least commonly triggered panels.
Federal law governs -- state law does not apply
Marijuana is federally controlled regardless of state law. A positive THC result is disqualifying even if you hold a state medical marijuana card and live in a state with legal recreational cannabis. There are no exceptions.
The MRO is a licensed physician certified in DOT substance testing regulations (49 CFR Part 40). Every DOT drug test result -- positive, negative, and otherwise -- goes through MRO review before it is reported. The MRO is a quality check and due process mechanism built into federal law.
When the lab reports a positive
The MRO contacts you directly (usually by phone) to ask if you have a legitimate medical explanation -- such as a valid prescription for an opiate pain medication. You have the opportunity to present your prescription documentation to the MRO.
Prescription medications
If you have a legitimate prescription that explains the positive screening, the MRO can designate the result as negative. Do not tell the collection site about your prescriptions -- save that for the MRO call if needed.
Result designations
The MRO can report a result as: Negative, Positive, Refusal to Test (adulterated or substituted specimen), Test Cancelled, or Negative with remarks. Only a Negative result clears you for the NMC application.
Refusal to test
Refusing to provide a sample, adulteration of the sample, or substitution of the sample are all treated as a Positive result under DOT rules. The MRO reports these as a Refusal to Test, which has the same consequences as a confirmed positive.
Drug Test Validity Window
The NMC must receive your complete application within 185 days of the drug test collection date. This is the collection date -- not the result date, not the postmark date. If your application sits on your desk past the 185-day mark, you must retest. Do not collect your drug test more than 4-5 months before you intend to submit.
A confirmed positive drug test result has serious consequences for your MMC application and future maritime career. Understanding the process helps you navigate what comes next.
A positive result does not permanently bar you from ever receiving an MMC, but the return-to-duty process is structured and takes time:
Complete an evaluation with a DOT-qualified Substance Abuse Professional (SAP). The SAP assesses the severity of the issue and recommends treatment or education.
Complete the treatment or education program recommended by the SAP. This could be outpatient counseling, intensive outpatient treatment, or inpatient rehabilitation depending on the SAP's assessment.
Pass a return-to-duty drug test administered under DOT protocols, supervised by the SAP process.
Complete follow-up testing as directed by the SAP -- typically 6 unannounced tests over 12 months after return to duty.
Reapply to the NMC with documentation of SAP evaluation completion, treatment completion, and negative return-to-duty test.
Second positive result: A second confirmed positive drug test after completing the SAP return-to-duty process is generally permanently disqualifying for maritime licensing.
Getting your captain license does not end your drug testing obligations -- it begins them. If you use your license commercially, you are subject to the DOT maritime drug and alcohol testing program under 46 CFR Part 16.
All licensed mariners who operate commercial vessels or vessels carrying passengers for hire must be enrolled in a DOT-compliant drug and alcohol testing program under 46 CFR Part 16. This includes OUPV (6-pack) license holders operating charter or hire vessels.
DOT sets minimum annual random testing rates. For maritime: 50% of covered employees must be tested for drugs each year, and 10% for alcohol. Individual employees may be selected for testing more than once in a year.
Most small operators use a Third-Party Administrator (TPA) to manage their testing program. The TPA maintains the random selection pool, notifies selected employees, and keeps records required by 46 CFR Part 16. Cost is typically $100-300 per year for small operators.
Beyond random testing, DOT maritime rules require drug and alcohol testing following serious marine incidents -- injuries, significant property damage, groundings, and collisions. The test must occur as soon as practicable after the incident.
If you hold a captain license but use it only for personal boating -- not for commercial hire, charter, or carrying paying passengers -- you are not subject to the ongoing random testing program. The requirement triggers when you operate commercially under your license. OUPV license holders running a charter fishing boat, a sailing school, or any paid passenger operation are subject to 46 CFR Part 16 testing requirements and must be enrolled in a compliant testing program.
The Transportation Worker Identification Credential (TWIC) is required for all MMC applicants. The TWIC background check is separate from the drug test and physical -- it is a security threat assessment conducted by the TSA under the Maritime Transportation Security Act.
Criminal history (federal and state), immigration status, terrorist watchlists and databases, disqualifying criminal offenses under MTSA, and identity verification via biometrics (fingerprinting).
Certain drug trafficking convictions, murder, espionage, terrorism-related offenses, and other serious crimes are permanently disqualifying. Some other offenses are interim disqualifying and may be waived. The full list is in 49 CFR Part 1572.
Apply at a TSA enrollment center (operated by IDEMIA). Pre-enroll online at universalenroll.dhs.gov. Bring identity documents. Fingerprinting is done in person. Cost is approximately $125. Processing takes 4 to 8 weeks.
Applicants with potentially disqualifying offenses who believe they qualify for a waiver can apply through TSA. The waiver process involves submitting documentation and explaining why the disqualifying factor should not prevent issuance. Not all offenses are waivable.
Apply for TWIC first -- it takes the longest
The TWIC card typically takes 4 to 8 weeks to arrive after your enrollment appointment. This is the longest single step in the licensing process. You cannot receive your MMC without a valid TWIC card in hand. Apply as soon as you decide to pursue your license, even before you complete sea time documentation or schedule your physical and drug test.
USCG uses a fitness-for-duty framework rather than a rigid list of automatic disqualifiers. The question is whether your medical condition poses an unreasonable risk to the safety of the vessel or those aboard. Many conditions that are controlled by medication or treatment are not disqualifying.
Waiver possibility:
Possible with documentation of control, seizure-free period, and specialist evaluation
Waiver possibility:
Possible with cardiologist clearance, stress test results, and demonstrated stable condition
Waiver possibility:
Case-by-case evaluation; stable, treated conditions with psychiatrist clearance may qualify
Waiver possibility:
Possible after SAP evaluation, treatment completion, and documented sobriety period
Waiver possibility:
Color vision restriction notation rather than full disqualification in most cases
If you have a medical condition that may be disqualifying, you can apply for a waiver through the NMC. The waiver application typically requires:
Waiver decisions are made by the NMC medical department. Processing times vary. Applicants with complex medical histories may benefit from consulting a maritime attorney or a physician with USCG credentialing experience before applying.
Many mariners take prescription medications. The presence of prescription drugs does not automatically disqualify you, but there are specific rules about disclosure and evaluation.
You must disclose all prescription medications to the physician performing your CG-719K physical. The physician evaluates whether any medications affect your fitness for duty. Common evaluations include:
Do not proactively disclose your prescriptions to the collection site before the drug test. The collection process must be unaffected by pre-test disclosures. Instead, if you test positive for a substance that you have a legitimate prescription for, the MRO will contact you after the laboratory reports the positive result.
When the MRO calls, you can provide:
If the MRO verifies the legitimate prescription, they can designate the result as negative. This is a standard part of the DOT MRO review process and is why the MRO system exists.
Opiates and ADHD medications -- plan ahead
If you take opiate pain medications or stimulant ADHD medications (which are controlled amphetamines), expect the drug test to flag positive. Have your prescription documentation ready for the MRO call. The process works correctly when you engage with it -- the MRO call is your due process opportunity, not an accusation.
Your MMC is valid for 5 years. When you renew, you must complete a new CG-719K physical examination and a new DOT drug test. Medical standards remain the same at renewal as at original application.
USCG requires a physical examination documented on Form CG-719K. The exam must be performed by a licensed physician (MD), Doctor of Osteopathy (DO), Nurse Practitioner (NP), or Physician Assistant (PA). The physical covers vision acuity, color vision, hearing, blood pressure, cardiovascular health, and general fitness for duty. The completed CG-719K is valid for 12 months from the date of the examination when submitted to the National Maritime Center as part of your MMC application.
USCG vision standards require distant visual acuity of at least 20/200 in each eye, correctable to 20/40 or better in the better eye and 20/80 or better in the other eye. Corrective lenses (glasses or contacts) are permitted. Color vision must also be tested -- the standard Ishihara plate test or equivalent must show the ability to distinguish the red and green colors used in navigation lights. If you fail standard color vision tests, alternative tests (Farnsworth D-15, City University) may be used, or you may qualify for a license with a restriction notation.
USCG requires a 5-panel urine drug test collected at a DOT-certified or SAMHSA-certified collection site. The test screens for marijuana (THC), cocaine, amphetamines, opiates, and phencyclidine (PCP). The result must be negative, and it must be reviewed and certified by a Medical Review Officer (MRO). Federal maritime law governs the test -- state-legal cannabis and medical marijuana cards are irrelevant. The NMC must receive your application within 185 days of the test collection date.
A Medical Review Officer (MRO) is a licensed physician with specialized training in drug and alcohol testing. Under DOT regulations (49 CFR Part 40), all DOT drug test results must be reviewed by an MRO before they are reported to the employer or agency. The MRO reviews the laboratory results, contacts the donor if there is a positive or unusual result to ask about legitimate prescription medication explanations, and then makes a final determination of negative, positive, refusal to test, or cancelled. The MRO is your point of contact if you have a prescription that could explain a positive screening.
The standard DOT 5-panel urine drug test screens for: (1) Marijuana metabolites (THC-COOH) -- detection window up to 30 days for chronic users; (2) Cocaine metabolites (benzoylecgonine) -- detection window 2-4 days; (3) Amphetamines including methamphetamine -- detection window 2-4 days; (4) Opiate metabolites including heroin, codeine, morphine -- detection window 2-4 days; (5) Phencyclidine (PCP) -- detection window up to 8 days. Detection windows are averages and vary by individual metabolism, hydration, body fat, and frequency of use.
Yes. Once you hold a USCG captain license (MMC) and work as a mariner, you are subject to the DOT maritime random drug testing program under 46 CFR Part 16. If you operate a vessel that carries passengers for hire or is a commercial vessel, you must be enrolled in a DOT-compliant drug and alcohol testing program. Random testing pools are typically administered by third-party administrators (TPAs). Testing rates are set annually by the DOT -- currently 50% for drugs and 10% for alcohol of the covered workforce per year.
USCG physical standards require blood pressure to be below 160/100 mmHg at the time of the examination. Blood pressure that is controlled by medication to within acceptable limits is generally acceptable, but the examining physician must note the condition and medications on the CG-719K form. Uncontrolled hypertension above 160/100 mmHg will require evaluation and may require a waiver depending on the severity and associated conditions.
USCG uses a fitness for duty standard rather than a strict list of automatic disqualifiers. Conditions that may be disqualifying include: uncontrolled epilepsy or seizure disorders, severe cardiovascular disease (recent MI, uncontrolled arrhythmia), insulin-dependent diabetes that poses an operational risk, severe psychiatric conditions, substance use disorders (active), and certain vision or hearing conditions below minimum standards. Many conditions that are controlled by medication or treatment are not disqualifying. A waiver process exists through the NMC for mariners with medical conditions that do not pose an unreasonable safety risk.
The CG-719K physical examination is valid for 12 months from the date it was completed. The NMC must receive your application within that 12-month window. If the physical expires before submission, you must complete a new examination. For renewal applications, a new physical is required. Note: some sources historically cited a 2-year window for original applications -- always verify current NMC requirements at the time of your application, as standards can be updated.
A positive drug test result reported by the MRO will result in the NMC denying your MMC application. The positive result is entered into the USCG Drug and Alcohol Clearinghouse. You may not reapply until you have completed a Substance Abuse Professional (SAP) evaluation, followed the recommended treatment plan, and received a return-to-duty clearance from the SAP. A second positive result is generally permanently disqualifying. Refusing to test is treated the same as a positive result.
Yes. You must disclose all prescription medications to the examining physician during the CG-719K physical. The physician will evaluate whether any medications affect your fitness for duty. For the drug test, if a prescription medication could explain a positive screening result (such as opiates from a legitimate prescription), you should disclose this to the MRO during their review call -- not to the collection site before the test. The MRO has authority to verify prescriptions and designate a result as negative if a legitimate medical explanation exists.
The Transportation Worker Identification Credential (TWIC) is a federal biometric identity card issued by the TSA that requires a security threat assessment and criminal background check. For MMC applicants, holding a valid TWIC card satisfies part of the security vetting requirement. The TWIC background check screens for criminal convictions that would disqualify a person under the Maritime Transportation Security Act (MTSA). Disqualifying crimes include certain drug offenses, violent crimes, and terrorism-related offenses. The TWIC costs approximately $125, is valid for 5 years, and takes 4-8 weeks to process. Apply early -- you cannot receive your MMC without a valid TWIC.
Full overview of USCG captain license types, requirements, and what you can do with each credential.
Step-by-step guide from sea time through exam to receiving your Merchant Mariner Credential.
Detailed walkthrough of every step in the NMC application process with forms, fees, and timelines.
Complete guide to the TWIC card -- who needs it, how to apply, costs, and what the background check covers.
Detailed breakdown of all CG-719K physical exam requirements including vision, hearing, and cardiovascular standards.
How to document sea service days, what counts, and how to fill out USCG sea service forms.
While your physical, drug test, and TWIC are processing, get ahead on the exam. NailTheTest has 1,600+ USCG exam questions with spaced repetition, section-by-section progress tracking, and detailed explanations. Free to start.
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