Thisconditioncan beachieved by using size-exclusionmembranesor by using anolyte (electrodialysis) membranes which operatein the presence ofdense electric charges.
Federal legislation passed in 1996 says that if you have "credible coverage, " which the large majority of employer-provided coverage is, the new employer's coverage cannot impose a pre-existing conditionexclusion.
But so far, none of the Bells has met the market-opening conditions for their local franchises that were laid down in the 1996 telecommunications act as a condition for ending their exclusion.