BOSTON, Mass. (SHNS)--Not all Bay Staters who have diabetes, asthma or heart conditions will benefit from the new prescription drug reform law, and a top health official signaled regulators may need to consider expanding cost-control provisions in the future. Members of the Health Policy Commission board discussed the gap in health insurance coverage Thursday. HPC Executive Director David Seltz highlighted how the law limits out-of-pocket costs for certain drugs to treat diabetes, asthma and the two most prevalent heart conditions. Drug law will target costs, access, PBMs "This mandate will apply to MassHealth, the Group Insurance Commission and to fully insured commercial health plans, and the legislation asked the Health Policy Commission to evaluate the impact of this new program every two years," Seltz said. HPC Commissioner Alecia McGregor later asked Seltz which groups of health insurance enrollees, such as MassHealth Connector members, are potentially left out of the copay limits of $25 for certain brand-name medications. Seltz said the caps apply to plans through the state's health insurance marketplace, but not to self-insured plans. In a self-insured plan, which is more common among large companies, employers collect premiums and are responsible for paying medical claims from employees and their dependents, according to federal health officials. Sen. Cindy Friedman, a lead bill negotiator, told the News Service on Thursday evening that self-insured plans aren't included because the federal government doesn't allow Beacon Hill to mandate that the plans follow this type of state law.  "I don't know what percentage of enrollees that might compromise, but I would imagine a fairly large share," McGregor said. HPC Commissioner David Cutler chimed in, telling McGregor, "It is not a trivial matter at all." "I'm guessing it's about half of the privately insured, just as a round guess," Cutler said. "Because almost all of the big employers are going to be self-insured, and then some of the smaller ones." Seltz did not specify the number of Bay Staters enrolled in their employers' self-insured plans, but he suggested the law may need to be expanded in the future. "In many cases where the state has made a mandate for coverage of the benefit, or in this case a copay cap on the fully insured market, there are times when self-insured plans will follow that same mandate in their plan design. They're not required to, but they may," Seltz said. The HPC can examine how self-insured plans choose to respond, and regulators can also make policy recommendations as they evaluate the impact of the new law. Seltz said regulators can explore how the law benefits patients and reduces long-term costs. "That may be something that we can help demonstrate in our analysis and in our reviews to make the economic case that this should be more widely applicable," Seltz said.