Looks like it'l officially have 26 episodes:
http://www.animenewsnetwork.com/dail...isodes/.101863

P.A. Works revealed on Thursday that the Kuromukuro television anime series will be two cour and will have 26 episodes. The anime premiered in Japan on Tokyo MX on April 7. The anime celebrates the 15th anniversary of the studio.

Netflix had announced on April 7 that it had the exclusive worldwide streaming rights to the anime. The announcement stated that Netflix will stream the series in other countries at a later date, but did not give any other specifics about streaming debuts outside of Japan. The website is currently streaming the series with English subtitles on Netflix in Japan.