In most cases, the actual verbiage turns out to be that the insurance for which you choose to enroll starts the first day of the month after your first 30 days of employment. However, it does not mean 30 work days, it means 30 calendar days.

So, if you start a new job on July 6, for example, you actually would not be eligible for insurance until September 1. Most companies like to start the new insurance at the beginning of a month, versus mid-month.

Just so you know, insurance companies (carriers) recommend a waiting period to employers because enrolling new participants takes a bit of time to do and costs money in administration. So, a waiting period ensures that the new employee has time to select what coverage she can afford and wants to have and that the new employee lasts in the job for at least the waiting period.

First-day coverage is just about unheard of these days. Many companies actually have a 60 or 90 day waiting period for benefits--so this sounds like a good company/employer.

Hope that the new job works out well for you in every respect.