The MHPA applies to group health plans for plan years beginning on or after January 1, 1998. The original
sunset provision provided that the parity requirements would not apply to benefits for services furnished on or after September 30, 2001. It was extended six times, with the final extension running through December 31, 2007. Insurers promptly were able to "circumvent" the consumer protections arguably intended in the legislation by imposing maximum numbers of provider visits and/or caps on the number of days an insurer would cover for inpatient psychiatric hospitalizations. In essence, the law had little or no effect on mental health coverage by group insurance plans. The rider on TARP prohibits all group health plans that offer mental health coverage from imposing any greater limit on co-pays, co-insurance, numbers of visits, and/or number of days covered for hospital stays due to mental health conditions. The rider legislation was the culmination of a long campaign fought by Sen.
Paul Wellstone (D-MN) and his successors to enact mental health parity at the federal level. The new law's requirements will be phased in over several years ==Requirements==