There is no village center named "East Merrimack"; rather, the CDP refers to the region of the town of Merrimack lying east of the F. E. Everett Turnpike, overlapping portions of the villages of Reeds Ferry, Thornton's Ferry, and the center of Merrimack.

The Everett Turnpike is accessible from Exit 11 (Continental Boulevard) near the southern end of the CDP and from partial Exit 12 (Bedford Road) near the north end.

As of the census of 2010, there were 4,197 people, 1,928 households, and 1,093 families residing in the CDP.

34.2% of all households were made up of individuals, and 11.3% were someone living alone who was 65 years of age or older.

Male full-time workers had a median income of $44,911 versus $46,933 for females.