It was only 3 years before. Currently it is 5 years. https://support.google.com/nexus/answer/4457705?hl=en https://support.google.com/nexus/answer/4457705?hl=en

It was only 3 years before. Currently it is 5 years. https://support.google.com/nexus/answer/4457705?hl=en https://support.google.com/nexus/answer/4457705?hl=en Note that major OS updates != security updates.