Net present value, an economic standard method for evaluating competing long-term projects in capital budgeting
National Popular Vote Interstate Compact, an initiative in the United States to elect the presidential candidate with the most votes nationwide
In medicine and science:
Negative predictive value, in biostatistics, the proportion of patients with negative test results who are correctly diagnosed
Nuclear Polyhedrosis Virus, a virus that infects butterflies and moths
Negative Phase Velocity, an electromagnetic property induced by some exotic optical materials
Negative pressure ventilator, a type of mechanical ventilator that stimulates an ill person's breathing by periodically applying negative air pressure to their body to expand and contract the chest cavity.
De Nederlandse Padvinders (Netherlands Pathfinders), a precursor to Scouting Nederland, the national scouting organisation of the Netherlands