What Maricopa County Assessor's Office does

The Maricopa County Assessor's Office is a county-level government agency, established in 1890 and headquartered in Phoenix, Arizona, responsible for identifying, locating, and valuing all real and personal property parcels within Maricopa County for property tax purposes. The office administers more than 1.8 million parcels with a combined full cash value exceeding $1 trillion, serves approximately 1.75 million property owners with annual Notices of Value, and supports the allocation of over $650 million in annual property tax revenue across county, city, town, and district jurisdictions. It operates as a statutory public service rather than a commercial enterprise: it does not generate revenue, does not charge fees for core assessment services, and is funded through the county budget.

The office's core technology platform is AA-GAMA (Assessment Analyst-Geographic Assisted Mass Appraisal), a cloud-based mass appraisal system launched in October 2022 that replaced a 1992-era platform and is complemented by the GIS-integrated Parcel Viewer and a vendor partnership with Esri Canada for Project MARS. Supporting digital services include an online customer portal for appeals, exemption applications, and rental registration; eNotice electronic delivery; virtual appointments via Microsoft Teams; DocuSign-enabled Notice of Claim filing; and, as of March 2026, free bulk data downloads. The office is led by elected Assessor Eddie Cook (appointed February 2020, elected November 2020), who has driven a Digital First modernization agenda and championed multiple pieces of state legislation including SB 1479 (deed fraud protection, 2026) and HB 2173 (electronic communications modernization, 2026).

The office's customer base is universally distributed across Maricopa County's 4.6 million residents and is segmented into residential, commercial/business personal property, agricultural, and special-use property owners, served via mailed notices, a self-service web portal, in-person service at Phoenix headquarters and a Tempe satellite office, and virtual appointments. Distribution is mandated by statute rather than commercially driven, and the office has been recognized through multiple workplace awards, including the 2026 USA TODAY Top Workplaces designation and multiple AZ Central Top Workplaces honors.

Name

Maricopa County Assessor's Office

Legal name

Maricopa County Assessor's Office

Website

https://mcassessor.maricopa.gov

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

51–100 employees

Short description

The Maricopa County Assessor's Office is a Phoenix-based county government agency that annually identifies, values, and administers assessments for more than 1.8 million property parcels with a combined full cash value exceeding $1 trillion, serving approximately 1.75 million property owners across Maricopa County, Arizona.

Ownership category

akta.pro rank

Product category

Government Property Tax Assessment

NAICS

Offices of Real Estate Appraisers (53132)

SIC

Real Estate (6500)

akta.pro primary industry

Municipal Tax & Revenue Administration (Local) (BPAIACAD)

akta.pro secondary industries

Real Estate Valuation & Appraisal (BPAHANAC), Commercial Property Appraisal (BPAJAKAB), Special-Purpose Property Appraisal (Healthcare, Religious, Public, etc.) (BPAJAKAG)

Keywords

• Property tax assessment
• Mass appraisal systems
• Parcel valuation services
• Government property records
• Tax exemption programs

Headquarters

HQ city

Phoenix

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2C

Offering type

Services

Cost components

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

Revenue model

1. Property Tax Assessment Services: As a government office, the Maricopa County Assessor's Office does not generate revenue. It is funded by the county budget and serves as the foundation for property tax allocation. The property values it determines serve as the foundation for fairly allocating more than $650 million in property tax revenue for Maricopa County and its cities, towns, and districts annually.

Go-to-market motion2 records

Distribution channels4 records

Marketing channels6 records

Core offering

The Maricopa County Assessor's Office identifies, locates, and values each parcel in Maricopa County to ensure fair and equitable property tax assessments, administering over 1.8 million real and personal property parcels annually with a Full Cash Value exceeding $1 trillion. The office issues annual Notices of Value, administers property tax exemption and valuation relief programs (including Senior Valuation Protection, Personal Exemptions for veterans and disabled persons, and Organizational Exemptions), processes valuation appeals, handles Business Personal Property (BPP) e-filing, and provides digital self-service through an Online Customer Portal, Parcel Viewer/GIS mapping tools, and electronic notices.

Product overview

The Maricopa County Assessor's Office operates as a government agency providing property valuation and assessment services rather than a commercial product company. The core service is the AA-GAMA (Assessment Analyst-Geographic Assisted Mass Appraisal) system, a cloud-based mass appraisal system launched in October 2022 that manages 1.8 million property assessments annually. Supporting this core system are digital service modules including an Online Customer Portal for property searches, appeals filing, exemptions applications, and Notice of Claims; the Parcel Viewer and GIS Portal for mapping services; eNotice for electronic notifications; Business Personal Property E-Filing; and the Maricopa Title Alert service. The office also administers valuation relief programs including Senior Valuation Protection and Personal Exemptions for veterans and disabled residents.

Differentiator

Problem solved

Functional benefit

Products and services

• AA-GAMA (Assessment Analyst-Geographic Assisted Mass Appraisal) System Cloud-based mass appraisal platform that identifies, locates, and values every real and personal property parcel in Maricopa County, supporting 1.8 million parcels with a Full Cash Value exceeding $1 trillion; integrated with the office's GIS for spatial analysis and historical trend reporting.
• Parcel Viewer (Maps) Interactive web-based mapping tool that allows the public to search and view parcel information, subdivision details, and MCR numbers across Maricopa County.
• GIS Portal Geographic Information System portal providing geospatial data and mapping services for property analysis and valuation support.
• Online Customer Portal Web-based self-service portal available 24/7 that allows property owners to register rental properties, apply for personal exemptions, file valuation appeals, submit Notices of Claim, update mailing addresses, and access property information.
• eNotice Service Voluntary electronic notification service that allows property owners to receive Notices of Valuation and other correspondence via email, with archives and reduced printing and postage costs to the County.
• Senior Valuation Protection Program Valuation relief program that may reduce property tax obligations for qualifying senior homeowners in Maricopa County.
• Personal Exemptions Program Property tax exemption program for qualifying widows, widowers, totally disabled persons, and veterans with service-connected disabilities residing in Maricopa County.
• Business Personal Property E-Filing Electronic filing system (Form 520) for business owners to submit annual Business Personal Property (BPP) reports to the Assessor's Office.
• Appeals Filing System Online and mail-based system for property owners and representatives to file commercial and residential valuation appeals, residential legal class changes, and residential rental property registrations.
• Bulk Data Downloads Portal Online portal providing free public access to detailed property datasets and bulk property reports, replacing a previously paid or formal-request-only process.
• Online Appeal Portal Electronic appeals portal enabling property owners and their representatives to submit commercial and residential valuation appeals online instead of by mail.
• Virtual Appointments 20-minute virtual appointments conducted via Microsoft Teams, scheduled online through Microsoft Outlook, providing remote face-to-face assistance for property owner inquiries.
• Digital Notice of Claim Filing Electronic filing channel for taxpayer Notices of Claim via DocuSign and email, enabled by Arizona SB 1266.

Quantifiable outcome

• Maintained nearly $500,000 under budget in Fiscal Year 2025 while serving 4.6 million residents and processing 1.8 million+ parcels.
• +3 more outcomes

Named customers1 record

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration4 records

Feature4 records

Partnerships

Six partnerships are on record, tiered core and minor.

• Representative Livingston (Legislative District 28)coreStrategic or Co-development Partner · 29 April 2026Representative Livingston of Legislative District 28 sponsored House Bill 2173, which modernizes electronic communications between property owners and the Assessor's Office during property error correction processes. Championed by Assessor Eddie Cook and signed into law by Governor Katie Hobbs.
• Arizona Legislature / Governor Katie Hobbs (Senate Bill 1479)coreStrategic or Co-development Partner · 20 April 2026Championed by Maricopa County Assessor Eddie Cook, Senate Bill 1479 was passed providing landmark legislation to protect Arizona homeowners from deed fraud. The bill was sponsored by Senator Frank Carroll, co-sponsored by Representatives Selina Bliss and Patricia Contreras, and signed into law by Governor Katie Hobbs. Key components include mandatory photo ID for in-person recording, statewide property owner alert system, and higher penalties for filing false documents.
• Maricopa County Recorder's Office (Maricopa Title Alert)minorStrategic or Co-development Partner · 1 January 2026Free public service document registration notifications provided courtesy of the Maricopa County Recorder's Office to help property owners safeguard their interests against title and deed fraud.
• Maricopa County Treasurer's OfficecoreStrategic or Co-development Partner · 21 July 2023The Treasurer's Office processes property tax refunds related to the Qasimyar class action and property tax bill issuance. The Assessor's Office submits tax roll corrections to the Treasurer for processing refunds. Treasurer contact for Class Action matters: [email protected].
• Esri Canada (Project MARS Vendor)coreTechnology or Integration · 13 October 2022Esri Canada is the vendor for Project MARS, the replacement mass appraisal system. The Maricopa County Board of Supervisors approved Project Change Request 05 for the contract with Esri Canada, with a single go-live date in February 2022. The system is a GIS-based mass appraisal platform.
• Mooney, Wright, Moore & Wilhoit, PLLC (Class Counsel)coreStrategic or Co-development Partner · 1 January 2016The law firm Mooney, Wright, Moore & Wilhoit, PLLC was appointed by the Court to represent all class members in the Qasimyar et al. v. Maricopa County class action lawsuit (Case No. TX2016-000882). Contact: 14301 N. 87th Street, Suite 207, Scottsdale, AZ 85260, Tel: 480-615-7500.

Scale indicators7 records

Recent moves9 records

Expansion highlights5 records

Broad incumbents

• Tyler Technologies: Tyler Technologies is the leading vendor of mass appraisal software (including the Aumentum suite) for U.S. county assessors and a broad incumbent whose products overlap with the operational space Maricopa's AA-GAMA addresses.
• CoreLogic: CoreLogic provides property data, analytics, and valuation tools widely used by county assessors and MLSs; a broad incumbent serving the same assessment ecosystem where Maricopa operates.

Others

• International Association of Assessing Officers (IAAO): IAAO is the global professional association for property assessment, of which Maricopa's senior appraisal staff are members; a thematic/ecosystem connection rather than a direct competitor, providing standards and credentials used across the office.

Direct peers

• San Diego County Assessor: San Diego County Assessor performs property valuation for California's second-most populous county; directly comparable in function, customer mix (residential, commercial, agricultural), and statutory framework to Maricopa.
• Harris County Appraisal District: Harris County Appraisal District performs mass appraisal for the Houston metro, comparable in scope, technology adoption, and parcel count to Maricopa's operations; serves as a closely matched large-county assessment peer.
• Cook County Assessor's Office: Cook County Assessor performs property assessment for Illinois' most populous county (Chicago metro); comparable in function, parcel volume, and large-county reform efforts, and frequently cited alongside Maricopa in mass appraisal modernization.
• Los Angeles County Office of the Assessor: LA County's Assessor performs property valuation and assessment for the most populous U.S. county, operating at similar scale (~2.5M parcels) and serving as the closest large-county functional peer to Maricopa in mass appraisal scope and complexity.
• Riverside County Assessor-County Clerk-Recorder: Riverside County Assessor performs mass appraisal for California's fourth-most populous county, with similar growth trajectory, residential/commercial mix, and operational scale to Maricopa.
• Clark County Assessor's Office (Nevada): Clark County Assessor performs property assessment for the Las Vegas metro; similar fast-growth profile and high parcel volume make it a near-regional peer to Maricopa with shared operational pressures.

Emerging players

• Vision Government Solutions: Vision Government Solutions provides appraisal and assessment software to municipalities and counties, an emerging vendor whose mass appraisal offerings intersect with the same operational space as Maricopa's AA-GAMA platform.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks2 records

Key highlights3 records

Customer concentration

• YouTubeyoutube.com/@MaricopaCountyAssessor
• LinkedInlinkedin.com/company/maricopa-county-assessor

Revenue estimate

Valuation estimate

Number of profiles

Profiles6 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 Maricopa County Assessor's Office