The Ackerman Academy fellowship, as other posters have said is an ACGME accredited fellowship. It may be "easier" to get a spot than other fellowships, just because there are more positions at that program than others. It is also a fellowship that may give you an opportunity to stay on as part of Dermpath Dx. I've heard rumors about some fellows paying for their spot..but I think these are foreign visiting fellows not under ACGME.
You apply to the fellowship as any other dermpath fellowship (not a match process). Just FYI, the program at Einstein and Path Associates (Port Chester) is also under the realm of Dermpath Dx.
http://www.dermpathdiagnostics.com/display.asp?catid=25&pageid=53
Regardless, a dermpath fellowship is a dermpath fellowship. Getting a spot and being board certified is what private groups are looking for first and foremost.