Hillsborough County New Hampshire: Government and Services

Hillsborough County is New Hampshire's most populous county, encompassing the state's two largest cities — Manchester and Nashua — along with 29 additional municipalities. The county government operates under a commissioner-led structure defined by New Hampshire RSA Title V (County Affairs), providing a defined set of services distinct from those delivered by municipal and state governments. This page covers the governmental structure, primary service functions, jurisdictional boundaries, and decision points that residents, professionals, and researchers encounter when working within Hillsborough County's administrative framework.

Definition and scope

Hillsborough County functions as an intermediate layer of government between New Hampshire's 221 incorporated municipalities and the state government seated in Concord. The county seat is located in Manchester. The county government does not replace municipal functions — it operates a parallel set of services mandated under state statute, primarily in the areas of corrections, social services, property records administration, and judicial support.

The county covers approximately 876 square miles and, according to the U.S. Census Bureau, holds more than 420,000 residents, making it the largest county by population in New Hampshire. That concentration of population means Hillsborough County administers the largest county-level caseloads in the state for programs including nursing care, welfare assistance, and criminal detention.

Hillsborough County is one of 10 counties in New Hampshire. For reference to the broader state government framework within which this county operates, the New Hampshire Government Authority provides a comprehensive reference baseline. Adjacent county structures — including Merrimack County and Rockingham County — operate under the same RSA Title V framework but serve distinct geographic and demographic profiles.

Scope limitations: This page addresses Hillsborough County governmental authority only. It does not cover the independent municipal governments of Manchester or Nashua, which operate under separate charters. State agency functions delivered within Hillsborough County — such as New Hampshire Department of Health and Human Services programs or New Hampshire Superior Court operations — fall under state rather than county jurisdiction and are addressed on corresponding state-level reference pages. Federal programs administered locally are also outside this page's coverage.

How it works

Hillsborough County government is governed by a 3-member Board of County Commissioners, elected by district to staggered 2-year terms under RSA 28. The commissioners hold executive and legislative authority over the county budget, direct county departments, and set county tax assessment rates.

The county's administrative structure includes the following principal elected offices and departments:

  1. Board of County Commissioners — Holds budget authority, sets the county tax rate, and oversees all county departments.
  2. County Sheriff's Office — Provides civil process service, court security, and transport of inmates; does not serve as primary law enforcement within municipalities.
  3. County Attorney's Office — Prosecutes felony-level criminal cases originating within Hillsborough County's jurisdiction (RSA 7:34).
  4. Register of Deeds — Maintains the official record of all real property transactions within the county; the primary repository for deeds, mortgages, and liens.
  5. Register of Probate — Manages the official filing records for estate and probate matters routed through the circuit court.
  6. County Nursing Home (Hillsborough County Nursing Home) — A licensed long-term care facility operated directly by the county, providing skilled nursing and residential care for eligible residents.
  7. County Department of Corrections — Operates the county jail, which holds pre-trial detainees and sentenced individuals serving terms under 1 year.
  8. County Human Services — Administers general assistance (county welfare) programs and oversees placement and care coordination for residents requiring county-funded nursing or residential services.

The county budget is funded through a property tax assessment levied on all municipalities within the county boundaries, apportioned by equalized property valuation under state formula (RSA 29:11).

Common scenarios

Residents and professionals interact with Hillsborough County government in a defined set of recurring contexts:

Decision boundaries

The line separating county authority from municipal and state authority is a frequent source of confusion. The following distinctions apply within Hillsborough County:

County vs. Municipal Authority:
- Road maintenance is a municipal responsibility for local roads and a state responsibility for state-numbered routes; the county holds no highway department function in New Hampshire.
- Local law enforcement is provided by municipal police departments (Manchester PD, Nashua PD, and 29 town departments); the Sheriff serves civil process and court functions, not patrol.
- Zoning, building permits, and land use decisions are exclusively municipal functions. The county has no zoning authority.

County vs. State Authority:
- The New Hampshire Department of Health and Human Services administers Medicaid, child protective services, and behavioral health programs within the county, but under state rather than county administration.
- Superior Court operations within Hillsborough County are part of the New Hampshire Judicial Branch (New Hampshire Superior Court), not the county government, even though facilities may be physically located in Manchester.
- Property tax rate-setting for schools and municipalities is a local and state function; the county sets only the county portion of the tax rate.

Hillsborough County's commission structure also differs functionally from a county executive model: there is no single elected county executive. All executive decisions require action by the 3-member commission acting collectively, which creates a distinct governance dynamic compared to counties in states where a county executive or county manager holds independent authority.

References