1 If X is a topological (or metric) space and M is a metric space, then the set of all bounded continuous functions from X to M forms a metric space if we define the metric as above: d (f, g) = sup x in X d (f (x), g (x)) for any bounded continuous functions f and g.
Invisalign is orthodontic appliance, so since orthodontic treatment is allowed as an FSA expense, Invisalign is covered. Different companies have different rules concerning amounts set aside and the timing of how funds are used for orthodontics.
In Minnesota there is a state statute that requires medical insurance to cover orthodontia for cleft palate children, however companies that are self-insured are not bound by the statute due to ERISA guidelines. We just ended a one-year appeal process with our employer (self-insured) but they will not budge.