It may different depending on the department, the individual resigning, and where the person is going to work. Typically, if you are going to a direct competitor, then your access will be revoked immediately and it will be your last day with the company. If you are not viewed as a good employee, then you may be told the same. The point is to minimize risk to the business. You should still be paid through the 2 week notification period.
If you're not going to a direct competitor, and you have knowledge that may need to be transferred or work transitioned, then you may be asked to work out the two weeks. In my experience though most people are starting to check out on day one of the two weeks. However, I can't emphasize enough the importance of leaving well, especially if you are staying in the employee benefits industry. There aren't that many degrees of separation for those of us in healthcare insurance. Don't burn bridges when you resign.
For example, I've had employees leave their role and work with me as their manager through the entire process, from telling me they are interiewing to me accepting their resignation. These are people I still stay in contact with. I would hire them back in a heartbeat. Conversely, I've had some turn in their resignation without so much of a hint prior. I don't think it was out of malice but rather ignorance. But if they ever came to me and asked for a job, I would have a hard time considering bringing them back on the team.