8till8,
There is no perfect time to start a health insurance policy but I would be inclined to say December 1 compared to March 28.
For the simple reason that sometimes there could be a list of price increases announced from March 1, so Dec 1 would avoid these.
It depends on the company, type of plan etc. The health insurance providers are getting more competitive around Dec/Jan months compared to
recent years, as the bulk of customers renew at that time of the year.
Regards, Snowyb