The NEC is available as a bound book containing approximately 1000 pages. It has been available in electronic form since the 1993 edition. The code is updated every three years. However, some jurisdictions do not immediately adopt the new edition.
The NEC is also available as a restricted, digitized coding model that can be read online free of charge on certain computing platforms. An external link to this online access is referenced at the end of this article.
In the United States, statutory law cannot be copyrighted and is freely accessible and copyable by anyone.
When a standards organization develops a new coding model and it is not yet accepted by any jurisdiction as law, it is still the private property of the standards organization and the reader may be restricted from downloading or printing the text for offline viewing. For that privilege, the coding model must still be purchased as either printed media or a CD-ROM.
Here is a link to California adopted codes.