Can mother-in-law be on son-in-laws health insurance?

The answer is yes if your place of employment offers sponsored dependent. My mother in law is under my insurance at work. She is a legal dependent according the IRS tax code. THere are not alot of places anymore with this provision but it is out there it is still not cheap We pay 400/month for her. Which is still cheaper then the 800.00 we were paying with Blue Cross blue shield privately