Sailors are encouraged to reach out to CGC by phone toll-free at 1-800-971-4288 or by email at CGCUSNavy@challengergray.com. Sailors who have been contacted by CGC and have a password for web access, can enroll at www.challengeressentials.com. For more information, access the transition assistance handbook on the Navy Personnel Command (NPC) ERB webpage or contact the NPC customer service center at 1-866-U-ASK-NPC (1-866-827-5672).