[2][non-primary source needed] In 1954, several dental service corporations formed in California, Oregon, and Washington.

These corporations were created by dentists who recognized the need to increase access to oral health care, and later joined to form Delta Dental.

[citation needed] A year later, the first multi-state program was sold by WDS to the International Association of Machinists.

The OCHAMPUS program led to the creation of the National Provider File (NPF), which was made available for commercial accounts in 1990 via Delta USA – providing Delta Dental coverage to organizations with employees and subscribers located in multiple states.

[clarification needed] Some dental providers charge that this practice reduces insurance competition and dictates prices for clinical services.