Area towns are reining in the cost of health insurance for their employees by adopting coverage plans with higher co-payments for doctor visits.

The changes have to be approved by employee unions, but officials say towns could save hundreds of thousands of dollars. The cost of health insurance will still increase next fiscal year, but not nearly as much as it would without the changes, Mansfield Town Manager John D'Agostino said.

He said Mansfield will save about $450,000, which will go toward balancing the town budget and avoiding layoffs.

The cost of insurance with the changes will increase between 2.6 percent and 3.2 percent, he said. Without the changes, the cost would jump 9 percent to 9.5 percent.

This year, the price of insurance shot up 12.5 percent, he said.

D'Agostino is head of a regional system with 19 member towns that developed new insurance plans for the towns. North Attleboro, Norton, Plainville and Seekonk are also members.

Judith Robbins, town administrator in North Attleboro, said insurance for North Attleboro employees is going up only 3.6 percent because of the changes.

Employees, if they accept the changes, will have to pay $15 for each visit to the doctor, rather than the current $5 fee, she said.

Co-payments for hospital visits will also rise.

Both the town and the employees would benefit from the lower premiums that result for the higher co-pays, she said. The town pays 75 percent of the premiums.

Attleboro is not a member of the group, but Mayor Kevin Dumas said increases have also moderated in the city.

The city is expecting a 5 percent increase in cost for the fiscal year beginning July 1. That compares with a 13 percent hike this year.

Attleboro is self-insured, and Dumas said the costs have moderated because of fewer claims by employees. The city has not changed the design of its plans, as surrounding towns have.

The smaller increases will save the school department $600,000 and the city $200,000, according to Dumas. The towns that want to change their insurance plans will have to get permission of the employee unions through what Robbins called "impact bargaining."

Whenever the conditions of a contract are changed, approval of employees is required.

D'Agostino said Mansfield wants to put $125,000 of its $450,000 savings aside in an account to reimburse employees for the higher co-payments.

The Massachusetts Teachers Association represents most of the local teachers' unions in the area.

Anne Wass, president of the association, said the union takes no official position on the changes in the local contracts. The MTA leaves it up to the local unions to decided what is best.

However, she said the MTA does insist that all changes be negotiated.

She said the cost of health insurance is a growing problem throughout the state.

Many local unions are reporting large increases in premiums, she said.

That is why the MTA supports a proposal by Gov. Deval Patrick to allow cities and towns join the less costly state system, she said.

Geoffrey Beckwith, executive director of the Massachusetts Municipal Association, said health insurance costs are still rising rapidly in the rest of the state.

The problem is that the cost of health care, itself, continues to rise, he said.

He said the only towns that have lowered costs are those that have switched to higher co-payments and higher deductibles.

D'Agostino said the changes local towns are making are similar to what has happened in the private sector, and he expects the trend to continue.