Due to unusually high call volume, you may experience longer than normal hold times. For faster service, use one contact method at a time, either phone, email, or live chat and a Customer Service Agent will be with you as soon as possible. We thank you for your patience and apologize for any inconvenience this may cause.

Customer Service Center

Excluding Federal Holidays, the Customer Service Center (CSC) is open Monday - Friday from 8 AM to 4:30 PM EST and closed every Thursday from 1 PM to 2 PM.

Address: 100 Forbes Dr. Martinsburg, WV 25404.
Phone (domestic):1-888-427-5662
Phone (international): 1-304-433-3400, Press option 0.
Email: iasknmc@uscg.mil (For general inquiries only)*
Fax: 1-304-433-3416
*DO NOT send applications or additional documentation to the IASK e-mail address as this WILL cause significant delays.

Online Chatting Service

Live Chat , Select the Live Chat button or Scan the QR Code 

For the quickest service, use one contact method, either phone, email, or live chat during operational hours.

QRcode Live Chat Scan Here.


Need to apply or send additional information (AI) for an EXISTING application? For FASTER service, send to:


Merchant Mariner Credential (MMC):

Medical Certificate:

  • All attachments MUST be in Adobe PDF format, otherwise your documentation will be returned causing further delays. The NMC cannot process attachments that are not in Adobe PDF format.

Customer Service Center Closures


Reminder on Thursdays from 1 pm to 2 pm EST CSC  agents are in Training.

During this time the phones and Live Chat are not available!

Please note the following exceptions to normal business hours (Monday–Friday,  8:00 AM–4:30 PM) for the National Maritime Center (NMC) Customer Service Center (CSC):

  • Monday, January 15, 2024 – Closed in observance of Martin Luther King Jr. Day.
  • Monday, February 19, 2024 – Closed in observance of Washington’s Birthday.
  • Monday, May 27, 2024 – Closed in observance of Memorial Day.
  • Tuesday, June 18, 2024 – the Contact Center will close at 2:30 PM EST.
  • Wednesday, June 19, 2024 – Closed in observance of Juneteenth National Independence Day.
  • Wednesday, July 3, 2024 – the Contact Center will close at 12:30 PM EST.
  • Thursday, July 4, 2024 – Closed in observance of Independence Day.
  • Monday, September 2, 2024 – Closed in observance of Labor Day.
  • Monday, October 14, 2024 – Closed in observance of Columbus Day.
  • Monday, November 11, 2024 – Closed in observance of Veterans Day.
  • Thursday, November 28, 2024 – Closed in observance of Thanksgiving Day.
  • Tuesday, December 24, 2024 – Open from 8:00 AM to 12:00 PM EST.
  • Wednesday, December 25, 2024 – Closed in observance of Christmas Day.
  • Tuesday, December 31, 2024 – Open from 8:00 AM to 12:00 PM EST.

*This holiday is designated as "Washington’s Birthday" in section 6103(a) of title 5 of the United States Code, which is the law that specifies holidays for Federal employees. Though other institutions such as state and local governments and private businesses may use other names, it is our policy to always refer to holidays by the names designated in the law. **July 4, 2020 (the legal public holiday for Independence Day), falls on a Sunday. For most Federal employees, Monday, July 5, will be treated as a holiday for pay and leave purposes. (See 5 U.S.C. 6103(b).)