This medal's obverse bears the seal of New York City. Around, · INTERNATIONAL ···· PHILATELIC · EXHIBITION · NEW · YORK · / MCMXIII; signed over roman year numerals, MAX BACHMANN.
The reverse bears a palm frond at left. On right side, AWARDED / TO / (cartouche) / FOR / (cartouche) / MCMXIII
Max Bachman also created a souvenir medal for the Exhibition's official banquet which was held on October 30, 1913. It shares this medal's obverse but has a different legend on the reverse.
The circular medals measure 41mm in diameter. I have seen both a silver and a gold award medal from this event. I assume that bronzes were struck as well but I do not know this for sure. No mintages are reprorted.