# Middlesex County Retirement System

Middlesex County Retirement System is a Pension Fund based in Billerica, United States.

## Overview

- **Organization type:** Pension Fund
- **Headquarters:** Billerica, United States
- **Region:** North America
- **Address:** 25 Linnell Circle, Billerica, MA 01865, United States
- **Founded:** 1911
- **Assets under management:** 2072 (Altss estimate)
- **Website:** middlesexretirement.org
- **LinkedIn:** https://www.linkedin.com/company/middlesex-retirement-system

## Regulatory record

- **Reports private funds:** No

## About

The Middlesex County Retirement System was established in 1911 to administer retirement, disability, and survivor benefits for county public workers. Thomas F. Gibson has led the board as Chairman-Treasurer for two decades while also providing legal counsel. Assets total $2.072 billion with 17.7 percent currently allocated to private equity against a 16 percent target. The system holds limited partner interests in Boston Millennia Partners, Globespan Capital Partners Funds IV and V, Ascent Venture Partners, North Atlantic Ventures, and Invesco funds. It also maintains a 2.9 percent timberland position through Global Forest Partners and several real estate fund interests including Realty Associates Fund VI and Ares Real Estate Group vehicles. Nearly all assets flow through the PRIT Core Fund in Boston. The system employs 13 professionals at its Billerica headquarters. It participates in the Massachusetts Association of Contributory Retirement Systems and the National Association of Public Pension Attorneys, where Gibson has served as past president. April 2024 board minutes reviewed operating budgets and investment allocations. Governance centers on an elected and appointed board that sets policy while delegating day-to-day investment execution to the state PRIM Board, creating a hybrid structure typical of smaller Massachusetts county systems.

## Sectors

- Pensions

## People

- Thomas F. Gibson, Esq. — Chairman-Treasurer
- Brian P. Curtin — Vice Chairman
- Lisa Maloney — Chief Administrative Officer

## Questions

### Who runs investment decisions at Middlesex County Retirement System?

The board sets policy under Chairman Thomas F. Gibson while day-to-day management occurs through the state Pension Reserves Investment Management Board via the PRIT Core Fund.

### Does Middlesex County Retirement System participate in fund commitments or only direct deals?

The system acts primarily as a limited partner in private equity, venture, and real estate funds and holds no disclosed direct company ownership.

### What investment stages does Middlesex County Retirement System typically target?

Through its fund commitments the system reaches early-stage venture, expansion, buyout, and mezzanine strategies across multiple managers.

### How is Middlesex County Retirement System related to MassPRIM?

It invests approximately 99.9 percent of assets in the PRIT Core Fund managed by the Pension Reserves Investment Management Board.

## Related profiles

- [Stadt Luzern](https://altss.com/profile/stadt-luzern)
- [UPS SCS, Inc. Employees' Pension Plan](https://altss.com/profile/ups-scs-inc-employees-pension-plan)

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Last updated: 2026-06-03T20:00:00.000Z

Canonical page: https://altss.com/profile/middlesex-county-retirement-system

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