What Cornerstone Management Systems does

Cornerstone Management Systems, Inc. is a third-generation, family-owned property management firm founded in 1978 and headquartered at 271 Madison Avenue, New York. The company provides full-service property management to Manhattan's small and mid-size residential cooperative and condominium buildings, with a current portfolio of more than 1,200 units and a stated 98% client retention rate.

The company's offering is organized into three core service modules: Property Management (day-to-day operations, preventive maintenance, staff supervision, code compliance, monthly board meetings, online bill payment portal, and 24-hour answering service); Financial Management (budgeting, reporting, capital planning, insurance review, leasing, and financing analysis); and Project Management (construction oversight for roof replacements, gas conversions, Local Law 11 facade work, energy improvements via NYSERDA, and renovations). The underlying technology stack is minimal and dependent on Appfolio, a third-party platform that provides the resident-facing online billing center with ACH and credit/debit payment processing; Cornerstone does not retain any portion of the Appfolio payment fees.

Cornerstone operates on a recurring management fee model, charging building owners and boards directly for ongoing services. Go-to-market is sales-led and reputation-driven: the firm captures leads via its website, a dedicated proposals email inbox, and direct outreach to Manhattan property owners and boards. The firm employs 13 staff including founding partners Leonard Fox (President) and Allen Abbani (Vice President/Controller), six property managers, and administrative personnel. The company has no external investors, no parent company, and no subsidiaries.

Name

Cornerstone Management Systems

Legal name

Cornerstone Management Systems, Inc.

Website

https://cornerstone-ny.com

Company type

Private

Founded year

1978

Operating status

Operating

Headcount range

1–10 employees

Short description

Cornerstone Management Systems is a third-generation, family-owned property management firm founded in 1978 that provides full-service property, financial, and project management to Manhattan's small and mid-size residential co-op and condo buildings, managing over 1,200 units with a staff of 13.

Ownership category

akta.pro rank

Product category

Residential Property Management

NAICS

Services to Buildings and Dwellings (5617), Facilities Support Services (56121)

SIC

Services-To Dwellings & Other Buildings (7340), Services-Facilities Support Management Services (8744)

akta.pro primary industry

Multifamily Apartment Property Management (BPAJAFAA)

akta.pro secondary industry

Master-Planned Community & POA Management (BPAJAHAD)

Keywords

• Residential property management
• Co-op and condo management
• Financial property management
• Building project oversight
• Manhattan property services

Headquarters

HQ city

New York

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Others

Revenue model

1. Property Management Services: Recurring management fees for full-service property management including day-to-day operations, financial management, and project oversight for residential co-ops and condos in Manhattan.
2. Online Payment Processing: Third-party payment processing through Appfolio. Cornerstone does not receive fees from credit/debit card transactions; only free e-check (ACH) payments are facilitated.

Pricing tiers

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

Cornerstone Management Systems provides full-service property management to Manhattan's small and mid-size residential properties, including cooperatives and condominiums. Its offerings span day-to-day property operations, financial management (budgeting, reporting, capital planning, insurance, leasing), and project management (construction, renovations, Local Law 11, NYSERDA energy improvements). The firm also operates an online billing portal powered by Appfolio for resident payments and a property listings service for available retail and residential spaces.

Product overview

Cornerstone Management Systems offers a unified property management platform with three core service modules: Property Management Services (day-to-day operations, maintenance, staff supervision, compliance, board meetings, and 24/7 answering service), Financial Management Services (budgeting, reporting, capital planning, insurance, leasing, and financing), and Project Management Services (construction oversight, renovations, and energy improvements via NYSERDA). The platform includes an Online Billing Center powered by Appfolio for payment processing and a Property Listings feature for showcasing available spaces. The company serves Manhattan's small and mid-size residential properties with a staff of 13 managing over 1,200 units.

Differentiator

Problem solved

Functional benefit

Products and services

• Property Management Services Full-service property management for Manhattan's small and mid-size residential properties, including day-to-day operations, preventive maintenance, supervision of building staff, code compliance, monthly board meeting attendance, monthly management reports, online bill payment portal, and 24-hour answering service.
• Financial Management Services Rigorous fiscal management including proactive budgeting, timely management statements and reports, long-term capital planning, insurance review and placement, commercial/residential leasing, and financing analysis and acquisition, delivered to co-op and condo boards and their accountants.
• Project Management Services Oversight and management of property improvement projects including project scoping, construction management, roof replacement, gas conversions, window replacement, Local Law 11 exterior maintenance, intercom system replacement, NYSERDA energy improvements, lobby/hall renovations, laundry room upgrades, and landscaping projects.
• Online Billing Center Digital payment portal integrated with Appfolio enabling residents to view and pay bills online via e-check (ACH) or credit/debit card, with options for automatic recurring payments, statement viewing, payment history management, and monthly reminders.
• Property Listings Online listing service showcasing available retail and residential spaces in Manhattan properties managed by Cornerstone, featuring property details, pricing, and availability information.

Quantifiable outcome

• 98% client retention rate
• +2 more outcomes

Segments2 records

Ideal customer profiles1 record

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

Scale indicators5 records

Recent moves4 records

Expansion highlights3 records

Direct peers

• Midboro Management: Long-standing NYC residential property manager specializing in co-op and condominium buildings across Manhattan. Directly comparable to Cornerstone in customer type, Manhattan geographic concentration, and full-service management approach.
• AKAM Associates: Long-established Manhattan-based residential property manager serving co-ops, condos, and rental buildings. Directly comparable to Cornerstone in target customer (NYC residential associations), service model (full-service management), and Manhattan small/mid-size building focus, though at significantly larger scale.
• Argo Real Estate: NYC property management and brokerage firm serving Manhattan residential co-ops, condos, and rental buildings. Comparable to Cornerstone in customer segment, Manhattan geographic focus, and bundled property/financial/project management service mix.
• Douglas Elliman Property Management: Property management division of one of NYC's largest residential brokerages, serving Manhattan co-ops and condos. Comparable in target customer and Manhattan geographic focus, with broader scale and brand recognition than Cornerstone.
• Maxwell-Kates: Manhattan-based boutique property management firm specializing in co-op, condo, and rental residential buildings. Closely comparable to Cornerstone in target customer, NYC boutique positioning, and full-service offering, with a similar emphasis on personalized attention to smaller buildings.
• New Bedford Management Corp: Manhattan-based property management firm serving residential co-op and condo buildings. Closely comparable to Cornerstone in target customer, single-market NYC focus, and traditional full-service property management offering.
• Brown Harris Stevens Residential Management: Established NYC residential property management arm of Brown Harris Stevens, serving Manhattan co-ops and condos. Directly comparable in target customer and full-service management model, with a similar focus on Manhattan's residential association market.
• Rose Associates: NYC-focused real estate management and development firm managing a large portfolio of Manhattan residential properties including co-ops and condos. Directly comparable in geography (Manhattan), customer segment (residential associations), and full-service management offerings.

Broad incumbents

• FirstService Residential: North America's largest residential property manager with a major NYC presence serving high-rise co-ops, condos, and luxury buildings. Overlaps with Cornerstone on customer segment and service lines but operates at vastly greater scale and with a broader national portfolio.
• Greystar Real Estate Partners: Global leader in residential property management, primarily multifamily rentals but with a growing NYC footprint. Comparable as a residential property management platform but operates at massive scale and is heavier on rental than co-op/condo association management.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks7 records

Key highlights6 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles9 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Cornerstone Management Systems