Trying to get my AB and have a question

I live up in Alaska and have my 100 ton masters with assisted towing endorsement, OS, Wiper,Food Handler on my MMD as well. I have my TWIC card too. I have tried to get my AB these past 2 years but have been having a bear of a time. I passed a course at my local college and got my AB certificate to give to the coastguard but they keep cancelling the proficiency in survival craft class. Both years they had too few of numbers. I went and submitted my paperwork anyways because by the time the 2nd one was canceled i was very close to the year expiration date on it.

I got a letter in the mail 3 months later saying that i needed to have my PSC. Is that really the case? I thought that that was more for STCW/international waters and that i could get my AB for US work. I have close to if not 540 days of sea time. I also just started up work and since i only work 6 months a year, i cannot miss any of it for the next 6 months for this class. Am i screwed? i really thought you didnt need the PSC to get an AB.

Thank you for your time and input. .

Yes you need PSC.

http://www.uscg.mil/nmc/checklists/pdfs/mcp_fm_nmc5_53_web.pdf?list3=%2Fnmc%2Fchecklists%2Fpdfs%2Fmcp_fm_nmc5_53_web.pdf&B2=GO!

You need psc as well as rfpnw to be considered a full AB

PSC is required for the AB rating; RFPNW is optional for the rating, but required by most companies, even for domestic routes.