The last two small firms I worked at, paid a set amount upfront $200 each month pre tax and the remainder based on the insurance company algorithms and the plan you as the employee chose was up to the employee to cover.  I think this is fare because if you hired a diabetic your insurance will go up drastically if you have a group plan in the traditional sense. A flat stipend for health insurance gives more choice to your employees and limits your small firm's risk when bringing on a new team member, it takes the possible temptation to discriminate out of the picture. It does however suck for the people who will be expensive to insure but the reforms from Obama care have impacted this a bit but it is still hard on them.  It sucks but small to medium firms have to think about the cost of bringing on employees if they will be expensive to insure, the larger the firm the more they can absorb the cost and distribute it to other employees

This is a question to ask an independent expert, try a few insurance brokers or the local or state small business bureau. 

My previous firm did the opposite and was very generous when it came to health insurance.  I paid $200 monthly, they picked up the rest- about $800 mo, for my family plan.  On the other hand I only pull low 40s in salary

An impossible thing to get right. I always paid all of it, hate the idea of nickel-diming employees. I think with 4 it may be hard to get a “group” rate, might be better to let everyone fly solo for now, more portable for them.

The problem with these things (insurance, time-off & bonuses) is the complaining if you choose wrong.

The thing I've seen most in the last couple years is firms that one way or another cut off half the cost. I had an interview at a firm that paid a specific amount extra in order to cover a portion of costs but employees had to deal with it themselves, it would have been about half price (small firm). Had another with a firm that had plans set up and paid for half of it (medium firm). The firm i ultimately got a job at was much larger so they self insured and made everyone pay full price, which ended up being about half of normal group insurance rates. At all three places the cost to me would have been similar.

my last firm paid 100%, 9 employees. they looked at it as a write off.

^ “write off”? A misused term used to imply that something doesn’t cost an employer anything….It’s all a write off, including your salary with regard to taxes (often used that way), but it’s actually an accounting term for say an account receivable that cannot be collected, you write it off your books as an asset…”write off” doesn’t = “free”, on the contrary in both cases.

2 person office: no coverage, but added a salary premium to cover $350/month

10 person office: dropped from 75% company paid to 50% when insurance premiums rose; option to buy in family coverage (at full price); also went from PPO to HD plan.

25 person office: 50%, option for family coverage with same 50% contribution, HMO/PPO options

I've also heard of firms contributing to HSA/FSA plans b/c it fixes their costs, while letting the employee pay the premium.

Since you don't offer it now, anything would be a plus for your employees.  Something flexible with fixed costs would seem the most fair.

Good to hear you're thinking of your staff. way to go!