Nonprofit health maintenance organization (HMO) Kaiser Permanente has partnered with Microsoft in its push for electronic consumer-controlled health records.

The partnership was first announced in June and is slated to begin with a pilot project open to Kaiser’s 156,000 employees.

If the pilot proves to be successful, a product linking Kaiser patient information with Microsoft’s Health Vault would be offered to Kaiser’s members.

“This is a big step for us, and our first partnership with a consumer health record supplier,” Anna-Lisa Silvestre, Kaiser’s vice president for online services told the New York Times.

Both Microsoft and Google, which offer platforms for electronic health record storage, previously announced collaborative projects with health providers. Microsoft’s partners included the Mayo Clinic and NewYork-Presbyterian Hospital. Google’s partnerships have involved the Cleveland Clinic and Beth Israel Deaconess Medical Center.

Silvestre said Kaiser looked closely at Google’s service but was impressed by Microsoft’s technology for protecting the privacy and security of data. Silvestre noted that Microsoft and Kaiser are using the same web-based format, called a Continuity of Care Document.

Kaiser Permanente is the nation’s largest nonprofit HMO with 8.7 million members.