Meeting government targets to provide care for the elderly has had an "adverse effect" on Highland Council's budget, a top official has warned.
Officials said it was delivering on a commitment for free personal care
Social work chief Harriet Dempster said it was delivering on a commitment to offer free personal care.
However, she said expenditure exceeded government funding allocated for it.
An extra £1.8m will also have to be found for specialist services for children, many of them referred from the Children's Panel.
On delivering care for the elderly, Ms Dempster said frontline staff have come under "considerable pressure" and a £2.4m overspend has been forecast.
Margaret Davidson, chairwoman of the council's housing and social work committee, said Highland was seeing an increasing number of people who required social work services.
She said: "Our budgets will have to catch up with this, but we are presently spending more than has previously been allocated.
"The council is clear that it will provide free personal and nursing care to all those who meet the criteria and that people will not remain unnecessarily in hospital. That costs money."
Officials have warned that council faces rising costs for external placements for looked after children.
These placements involve specialist care and educational support provided by residential schools outside the Highlands.
Liz MacDonald, the council's spokeswoman for children's services, said: "We have developed many services to support more young people within Highland, and staff in the council and voluntary sector have been particularly successful in their skilled work with young offenders.
"However, some young people, especially those with complex needs, will always need specialist support, and the cost of such placements has increased enormously in recent years."
Some Scottish councils are spending almost five times as much as others on providing free personal care for the elderly, according to a report released in the summer.
But the independent study, commissioned by the Joseph Rowntree Foundation, said the biggest spenders did not always provide the best service.
The report also suggested Scottish Government under funding was one of the main problems with the system.
The new administration has already commissioned a review of the scheme.