BOSTON -- Massachusetts' landmark healthcare reform bill promised affordable healthcare for all, but Commonwealth Care may be falling victim to its own success.

NewsCenter 5's Steve Lacy reported that there are new concerns about the state's mandated health care program.

The state is trying to figure out how to keep the plan affordable, but also wants to keep people from dumping their private coverage and joining the state's just to take advantage of the savings.

The number of enrollees is expected to double in the next three years.

The state is considering some rate hike changes, including increasing premiums by 14 percent and doubling co-payments for office visits and prescription drugs.

The plan is still in its preliminary stages. Some changes being considered would affect some 85,000 current low-income enrollees. They could see a 14 percent premium increase, meaning a $5 hike in the future for those currently paying the lowest premium. Co-payments for office visits and prescription drugs could also double.

Advocates for the poor fear that any kind of rate hikes could be devastating. Rate hikes could be lowered or eliminated altogether if the state can find money elsewhere to pay for the program or if they can find a lower rate from other insurers.