Effective from May 2006 (May 2007 for small health plans), all covered entities using electronic communications (e.g., physicians, hospitals, health insurance companies, and so forth) must use a single new NPI. The NPI replaces all other identifiers used by health plans, Medicare, Medicaid, and other government programs. However, the NPI does not replace a provider's DEA number, state license number, or tax identification number. The NPI is 10 digits (may be alphanumeric), with the last digit being a checksum. The NPI cannot contain any embedded intelligence; in other words, the NPI is simply a number that does not itself have any additional meaning. The NPI is unique and national, never re-used, and except for institutions, a provider usually can have only one. An institution may obtain multiple NPIs for different "sub-parts" such as a free-standing cancer center or rehab facility.