New York developer Michael Stern is joining in the frenzy over the latest U.S. real estate tax break, with four projects in “opportunity zones” on the East Coast.

Stern, whose JDS Development Group is also building ultra-luxury condos on Manhattan’s Billionaires’ Row, said he is investing with family offices in eligible sites in New York’s Brooklyn and Queens, and the Allapattah and Opa-Locka areas of Miami-Dade County, Florida.

Opportunity zones emerged as a component of the 2017 federal tax law,...