The North American Product Classification System (NAPCS) is a market or demand-based, hierarchical classification system for products (goods and services) that is not industry-of-origin based but can be linked to the NAICS industry structure and is consistent across the three North American countries. It is a system that has been phased in beginning in 1999 and can be used to drill down in industries.

For example, anyone looking for all the pharmacies in a particular area will want stand-alone pharmacies, pharmacies in grocer stores, and pharmacies in general purpose stores like Target and Wal-Mart. Since NAPCS operate a little differently than SIC and NAICS codes, the NAPCS code 342010103 includes Retailing services for medicines, vitamins, minerals, and supplements regardless of what the retail looks like.