In 1984, he moved the gallery to New York, and is currently a member of the Art Dealers Association of America (ADAA) and the Syndicat National des Antiquaires (SNA), France.
Museums and collectors in the United States and Europe frequently consult Moeller to obtain appraisals for works in their collections for exhibition, insurance, and estate purposes.
[3] For 30 years, Moeller was the curator and sole advisor of the Hon.John C. Whitehead until the latter's death in February 2015[4] a one-time co-chairman of Goldman Sachs and Deputy Secretary of State (US), whose collection of late 19th and early 20th century French masters has been exhibited in top institutions around the world.
Other recent exhibitions include Howard Wise Gallery: Exploring the New (2013), Crosscurrents in Modern Art (2013–14) and Lyonel Feininger: Master Printmaker (2014).
Moeller is a member of Rotary International, the American Council on Germany, the International Fine Print Dealers Association (IFPDA), the Catalogue Raisonné Scholars Association (CRS), the Honor Committee of Archivio Piero Dorazio, and the Friends of the Busch-Reisinger Museum, Harvard.