Mayor Toni Harp on Friday pitched a $510.8 million budget — asking taxpayers to chip in an additional 3.8 percent for a spending plan she said will stabilize the city’s fiscal future while protecting core services.

Harp’s proposal calls for a 2.7 percent increase in spending over last year’s $497-million budget. Much of the increase owes to rising fixed costs, Harp said, such as debt service, pension liabilities, medical benefits and contractual salary increases. The budget also sets aside an additional $1.5 million for the Board of Education and $2 million for long-term financial planning, including replenishing the city’s depleted rainy day fund.

To cover costs and lay the groundwork for boosting revenue, Harp proposed a rate of $42.36 in taxes for every $1,000 of assessed property value. That would mean a $1.56 rate increase over the current rate of $40.80 for the fiscal year beginning July 1.

Harp estimated that someone with a home valued at $150,000 would pay an additional $170 per year. She said the tax hike is the cost of expecting 21st-century city services.

“We’ve got to be realistic about what it is we want in terms of services from the city and realistic about how much they cost,” Harp said. Staff cuts and dwindling resources over the past 20 years have left the city ill-equipped to meet its current needs, including snow removal and information technology, Harp said.

The proposal now goes to the city’s Board of Alders. If the Board can find additional revenue or make further cuts, it is welcome to lower the mill rate, Harp said.

Budget Director Joe Clerkin said the most notable aspect of the budget is its structural soundness. The city will no longer build its fiscal future on short-term revenue boosts or one-time cuts, he said.

Daryl Jones, city controller, said the proposed budget seeks to move the city away from a “crisis management” mode. By engaging in strategic planning, Jones said, the budget office is setting a long-term plan for expenditures and expected costs.

Harp’s proposal includes a handful of new City Hall positions, including a director of minority and small business initiatives and a four-person grants-writing office. The Board’s finance committee hedged on that request earlier this month. Harp said all additions were offset by personnel cuts elsewhere.

Harp said reductions were also made in overtime spending in expectation of new classes of New Haven police officers and firefighters. All city department heads were asked to trim two percent from their budgets. Whether they succeeded or not, Harp said, small cuts were made across the board.

The Board’s finance committee will hold its first public hearing on the budget this Thursday at the Hooker Middle School.