Commissioners blamed most of the increase on the rising cost of dealing with troubled youth.
The county's department of Children and Youth Services is expected to grow by $1.1 million next year, from $3.9 million to $5 million, the budget shows.
"Even though we may feel shielded, we are directly affected by society's ills from juvenile crime and delinquency to drug and alcohol abuse," said Commissioner Robert L. Thomas. "It's the county government that's charged to pay for prosecution and sometimes defense. In the case of both juveniles and adults, rehabilitation."
Some juvenile offenders are sentenced to programs that cost $325 a day. The county must foot the bill.
The county hopes to attack the problem of juvenile crime and delinquency by hiring someone to develop youth programs, said Commissioner Cheryl S. Plummer.
Increases are also proposed in three other areas of county government - planning, farmland preservation and reuse of Letterkenny Army Depot.
"In some respect, I think we're playing catch-up. I think some initiatives we're doing are long overdue," said Commission Chairman G. Warren Elliott.
The $36,000 increase in farmland preservation funds will be used to leverage state and federal grants to purchase development rights of farms.
The redevelopment of 1,500 acres at the downsizing Letterkenny Army Depot is mostly being paid for by federal grants.
Even with the tax increase, county government will be financially strapped, said county Fiscal Director Jerry Frey.
"It'll be a belt-tightening year. Real tight. Uncomfortable, perhaps," Frey said.
Despite the proposed tax increase, the county plans to spend about $750,000 in cash reserves to balance the budget, he said.
There will still be adequate reserves, enough to operate the county for 85 days, he said.
County commissioners have been working on the budget for months with finance officers and department heads.
Residents can look at and comment on the proposed budget.
It can be seen at the commissioners' office on the second floor of the Court House, 157 Lincoln Way East, Chambersburg, Pa. It is also available at the borough halls of Waynesboro, Greencastle and Mercersburg and the municipal buildings of Southampton, Lurgan, and Metal townships.