TWIC Card vs Mariner Medical Certificate: What’s the Difference?

September 6, 2025

If you are just getting a job on the water, or if you’re renewing one of your credentials, the TWIC card and the Mariner Medical Certificate can be easily confused. They are both important, particularly in Florida, but they are for very different purposes.

And whether you’re a commercial mariner, boat captain or earning your license, understanding what each document does will help you avoid delays, remain in compliance, and keep your career on track.

We will simplify this – and also show you how to get each one without the headache.

What Is a TWIC Card?

A TWIC (Transportation Worker Identification Credential) card is provided to workers by the TSA (Transportation Security Administration).

You’ll need it if your job takes you into secure areas at ports, on vessels, or maritime facilities.

In short, the TWIC card:

Confirms your identity
Shows you’ve passed a federal background check
Allows you into restricted maritime zones without an escort

To get one, you apply online or at a TWIC enrollment center. You’ll need to provide fingerprints and bring documents like a passport or birth certificate and driver’s license. Once approved, your card is mailed to you.

What Is a Mariner Medical Certificate?

The Mariner Medical Certificate is issued by the U.S. Coast Guard (USCG) and proves that you’re physically fit to do your job safely on the water.

It’s based on a USCG-approved physical exam, usually done using Form CG-719K.

This certificate is often required when you’re applying for or renewing your Merchant Mariner Credential (MMC).

TWIC vs Mariner Medical: What’s the Difference?

These two documents often get confused, but they have totally different purposes:

What They’re For

TWIC: Gets you security clearance for restricted maritime areas

Medical Certificate: Confirms you’re physically able to work at sea

Who Gives It to You

TWIC: TSA (Transportation Security Administration)

Medical Certificate: USCG (U.S. Coast Guard)

How to Get It

TWIC: Apply online or in-person at an enrollment center

Medical Certificate: Do a physical exam with an approved provider, submit with your MMC application

How Long It’s Valid

TWIC: 5 years

Medical Certificate: Usually 2 years (1 year for some roles like STCW)

Do You Need Both?

Not always — but if you’re working on a commercial vessel, or applying for certain licenses in Florida, you’ll probably need both.

Do Recreational Boaters Need These?

If you’re just boating for fun, the answer is no — you don’t need a TWIC card or a Mariner Medical Certificate.

But if you’re shifting into charter work, fishing tours, or commercial boating, you probably will.

That’s where a Physical for Boaters Florida becomes important — especially if you’re going for a Captain’s License (like OUPV or Master). In that case, the medical certificate is required, and the TWIC card might be too if you’re operating in secure areas.

Applying in Florida: What’s the Process Like?

For the TWIC Card:

Visit the TSA’s TWIC website
Schedule an appointment at a Florida enrollment center (Miami, Tampa, Jacksonville, etc.)
Bring ID and payment
Wait for your card to be mailed to you
For the Mariner Medical Certificate:
Book a USCG-approved physical exam
Use Form CG-719K to record your exam results
Submit it with your MMC application through the National Maritime Center

There are clinics that handle Physical Examination for Mariners Florida and even help with the paperwork — which saves you time.

Can You Get Both at the Same Time?

Not really, they’re handled by different agencies. But here’s a smart tip:

Get your TWIC card first, then do your medical exam.

That way, if you’re applying for your MMC, you won’t run into delays because your TWIC is still processing.

Your Next Steps for TWIC and Mariner Physicals

A TWIC card lets you access secure maritime areas. A Mariner Medical Certificate proves you’re healthy and ready for the job. Both are necessary but have different uses.

If you’re on your way to a maritime career in Florida, knowing the difference now will save you anxiety later. Whether you’re booking your Physicals Exam For Mariners Florida or applying for your TWIC card, it’s always best to start early.