Most New Yorkers are taking their organs to the grave.

Only 22 percent of Empire State adults are registered organ donors — less than half the rate of the national average of 48 percent, according to a new study by insurance giant Blue Cross Blue Shield.

Among the 50 states, Washington DC and Puerto Rico, only Vermont (18 percent) and Puerto Rico (17 percent) had a lower rate of organ-donation registration.

In the five boroughs, Manhattan had the highest percentage of organ donation at 27 percent, far ahead of Staten Island (15 percent), Brooklyn (14 percent), Bronx (12 percent) and Queens (11 percent).

The top three states for organ-donor registration are Montana (84 percent), Alaska (83 percent) and Washington (80 percent).