100 Ngultrum Year of the Rat

Bhutan's lunar series coins are struck for the collector market and carry no meaningful circulation history — the ngultrum's everyday denominations are far more modest. The Year of the Rat falls first in the twelve-year Tibetan-Buddhist lunar cycle, a calendar system Bhutan shares culturally with Tibet, China, and much of the Himalayan world, though the kingdom's own Drukpa calendar runs concurrently and is considered the official reckoning for religious observance.

The Royal Monetary Authority has issued bullion and commemorative pieces of this type since the 1990s, largely through distribution agreements with international mints and numismatic agencies rather than domestic retail.