Stock options are complicated.
- Almost anything can fall under ERISA. Just fund it through an outside trustee and you have involked ERISA. Certain types of benefits (retirement plans including 401(k) and medical plans) must be ERISA, but other types of benefits might be ERISA.
- ERISA is enforced by DOL. If ERISA is in play, then there must be a formal written plan and the plan must be followed to the letter. I have done stock plans before, but ERISA was not involved.
- HOWEVER stock options are more commonly an IRS issue. Under IRC (different law), stock options can be qualified or non-qualified. ISO and ESPP are the most common types of qualified stock options, as are ESOP, which is something differnet. What all three of these have in common is that there are formal plan rules controlled by IRS and IRC (not ERISA). Past that, there are non-qualified plans, which are what they sound like, any plan which is not qualified. Qualified stock plans tend to have some sort of tax preference while non-qualified stock "plans" (which might not have an actual plan) do not. IRS pbulication 15B Fringe Benefits discusses the IRS stock rules in detail.
- Lastly, under Common Law, employers can normally change compensation on a go forward basis. However, if the employee was promised say $10/hr and only paid $8/hr, in theory there is potential recourse under Common Law. Adding stock or stock options does not change this principal. Second however is that claiming is not proving. The employer has many potential defenses including "a reasonable person would have gotten it in writing or checked the benefit plans". I have never worked for a company where managers were allowed to unilaterly do things like make stock option offers without going through normal channels. If nothing else, our formal published plans did not allow it and the wording of the published plans made it very clear that this was not allowed. We also tended to put specific "this is not a contract" language in all of our offer letters.