Does a cafeteria plan that offers a health FSA need to comply with Michelle's Law (amend the plan, provide the notice)? The plan does not define dependent child, it defines dependent as Section 105(b) dependent. Shoud we define dependent child for purposes of Michelle's Law?

If the FSA is an "excepted benefit," there is no need to comply with Michelle's Law. The cafeteria plan itself is not a group health plan and need not comply but any underlying other group health plans paid through the cafeteria plan that are not excepted benefits have to comply with the law.

Do you mean the caf plan defines dependent under Sec. 152? Regardless, there is no reason to amend caf plan because Michelle's Law doesn't change the definition of an IRS dependent (just extends medical coverage). Taxation under group health premiums and caf plans is based on IRS definition. Employers/carriers/fed law define dependent for purposes of coverage.