Yes, HAMBURG is a Scrabble word!

Letter values in Scrabble US: H 4, A 1, M 3, B 3, U 1, R 1, G 2.

Is it a valid word?

HAMBURG is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a port city in northern Germany on the Elbe River that was founded by Charlemagne in the 9th century and is today the largest port in Germany; in 1241 it formed an alliance with Lubeck that became the basis for the Hanseatic League