Data drawn from the Mercer National Survey of Employer-sponsored Health Plans in 1997 and 2003 indicate that a large majority of employers continue to provide some level of coverage for mental health (MH) services in their primary plans. However, a majority of plans continue to impose different benefit limitations for MH than for other medical treatment. Among plans with limitations on MH coverage, there was a sharp increase in the use of limits on inpatient days and outpatient visits between 1997 and 2003. The proportion of employers providing coverage for some MH services decreased; e.g., among small employers, 88% provided coverage for inpatient MH care in 2003, compared with 94% in 1997. These results suggest that parity legislation has had a noticeable but limited effect, but that, at least in the short-term, it is unlikely that universal parity in employer-based plans will be achieved through a legislative strategy.