Welcome to the Taxonomy Web Site

This site is a support tool which allows licensed subscribers to search the 211 LA County Taxonomy in a variety of ways, print the Taxonomy in various formats, download the file that will allow them to incorporate the Taxonomy in their database initially and keep it updated over time as the Taxonomy changes and grows, view recent changes and additions, and develop, save and share customized versions of the Taxonomy through the Filters function. Separate versions of the Taxonomy are available to U.S. and Canadian subscribers, the latter in both English and French. To change the view of the Taxonomy that is being displayed, click on "change" and select the locale you wish to see. For more information on the Canadian Taxonomy, click here: Canadian Taxonomy Development History.

What is a Taxonomy?

Taxonomies are sophisticated tools that help people find the information they need. They are a type of a controlled vocabulary, a standardized set of terms and phrases that are used to index and retrieve information about a particular subject in a systematic, unambiguous way. The 211 LA County Taxonomy sets a standard for defining services and for indexing and accessing the wide variety of human services available in communities across North America.

To Explore the Taxonomy

Visitors to the site are given only limited access that allows them to get a feel for the site’s structure, content and features before making a commitment to purchase a subscription.

To see examples of complete sections of the Taxonomy in printed form, follow these links: Disaster Services, Volunteer Opportunities. The Disaster Services section was developed in conjunction with the AIRS NERIN (National Emergency Resource Information Network) project in the mid-1990s and the Volunteer Opportunities section of the Taxonomy was developed in cooperation with the Points of Light Foundation. Both include an outline of the section's structure and a hierarchical listing of all terms with definitions, see also references, use references and bibliographic references. Both documents are governed by our Terms of Use.

Authorized Vendors

Please be aware that if you purchase or license a product or service that incorporates or uses the Taxonomy from a third party software/technology vendor who is not on the list of authorized vendors, you are not buying from a vendor authorized by 211 LA. Only 211 LA authorized vendors have access to the information and rights necessary to provide products and services that incorporate or use the Taxonomy. Please contact 211 LA at taxonomy@211la.org if you are using, have recently purchased or recently upgraded your I&R software from a vendor not on this list, to ensure that you or your agency are not subject to unauthorized use of the Taxonomy.

Also, please note that authorization for a vendor to incorporate or use the Taxonomy does not indicate any approval or endorsement by us as to the performance, features or quality of such vendor's products. 211 LA has not reviewed all of the products and services made available by authorized vendors and has no control over such products and services. Use of products and services made available by authorized vendors is subject to the privacy practices and terms of use established by the applicable vendor and we disclaim all liability associated therewith.

What others are saying about the Taxonomy

"Awesome breadth and depth and a rigorous methodology." — Deane Zeeman, Library and Archives Canada

"The most complete, almost encyclopedic taxonomy I've encountered covering a subject domain. It shows how a well developed taxonomy can enable learning and guide searchers to unforeseen, yet highly relevant topics." — Linda Farmer, MLS, Information Consultant, Second Knowledge Solutions

"The Taxonomy is straightforward, comprehensive, focused on human services; has amazing definitions; is easy to understand; and can be effectively used anywhere by anyone." — Diane Murdock, City of Calgary Information Centre

"The 211 LA County Taxonomy is to the information and referral field what the Library of Congress catalog system is to libraries, nationally and internationally. It allows all information and referral providers to speak the same language, classify information consistently, and share data locally, statewide, regionally, nationally and internationally. It is the crucial element in creating a national database in the future, that will both help identify gaps in service as well as make it faster and easier to get people connected to vital resources. It is a tool that maximizes access to community resources and actualizes the mission of information and referral." — Mary Hogan, Past President, AIRS Board

"The Taxonomy is both extensive and specific simultaneously.  As an organization that hears from thousands of young people each week, we require well-developed and defined terms for children and youth services Canada-wide. The Taxonomy allows us to satisfy both the needs of our professional counsellors, who provide information and give local referrals, as well as the needs of the children, youth and young adults who reach us by phone and online. We also appreciate the ability to suggest updates and make inquiries about the definition of particular terms." — Kristen Buckley CRS, Kids Help Phone

"The 211 LA County Taxonomy is known for its superb, comprehensive health and human services terms, but its government-related terms are equally impressive.  After an exhaustive review of all city departments and entities, the city of New Orleans selected the Taxonomy as the foundation for its comprehensive 311 Knowledgebase. The Taxonomy also became the basis of a citywide service catalog and is now the backbone of the new 311 system which uses Taxonomy terms to identify service and information requests. The Taxonomy editor worked closely with us to fill gaps that were identified during the project, and even created new terms as part of the process.  The citizens of the City of New Orleans now benefit on multiple levels from the tremendous resource which is the AIRS/211 LA County Taxonomy." — Jonathan R. Padgett, 311 Content Manager, City of New Orleans

"When Points of Light wanted to develop our own Taxonomy we found out who the expert was and it was AIRS and Georgia Sales, and together we were able to create a taxonomy for volunteer opportunities and volunteers within the AIRS/211 LA Taxonomy. This was one of the best partnerships I've experienced: Points of Light had the subject expertise and volunteer reviewers and Georgia had the encyclopedic knowledge of how to develop a taxonomy, and the framework of codes that saved us time, energy and effort." — David Styers, formerly with Points of Light Foundation

"Its beauty is that it is always changing/adapting to new concepts and services." — Lael Tryon, Greater Twin Cities United Way 2-1-1, Minneapolis

"Working in a small, specialty I&R, I love that we're able to show when services are intended for specific populations in a user-friendly way using target terms. We pay a minimal fee and no longer spend countless hours developing and updating our own system. The Taxonomy is a huge time saver!" — Katie Conlon, CRS, Iowa COMPASS, Center for Disabilities & Development

"The AIRS Taxonomy is an integral component of Bowman Systems' ServicePoint (R) software, which is used throughout the state of Michigan to manage and report on homelessness activities. The web-based nature of the system, along with built-in access to the taxonomy, enables many different types of agencies to work together within a single software system.  The AIRS Taxonomy gives staff across our entire provider network a "common language" to quickly and accurately identify services required, make timely and appropriate referrals, and record information about services provided. Perhaps most important, it allows us to pull statistics into reports that are relevant to each stakeholder individually, to the provider network, the community as a whole, and to funders." — Barbara Ritter, Michigan Statewide HMIS Project Director

"Using Taxonomy codes has made searching easier and faster. We would be lost without it!" — Betty Hanacek and Marioly Botero, United Way 2-1-1, Atlanta

"I&R is an important link to service provision for both populations of older adults and people with disabilities, and the AIRS/211 LA County Taxonomy is a key tool for developing and defining a common language that is understood by aging and disability I&R/A specialists. The aging and disability networks have a variety of program, service and funding crossovers, and therefore many resources in common. All of these resources are more easily accessed using the aging and disability specific terms that are pinpointed by the aging and disability filter available on the taxonomy website. The filter makes finding resources that much quicker, and more streamlined, as I&R/A staff are increasingly called to address the needs of new and growing populations." — The National I&R Support Center, Aging & Disability

"The Taxonomy serves as the underlying structure for our Community Disaster Information System. We have found the Taxonomy to be the most comprehensive categorization of community-based resources for disaster preparedness and response." — Douglas Troy, Professor, Miami University

"A well-structured and rich controlled vocabulary for human services." — Dr Ali Shiri, School of Library and Information Studies, University of Alberta

"The taxonomy would enhance open access to government as navigating through it is very intuitive and straightforward." — Andrew LeFrancq, Ministry of Government Services, Ontario Government

"Like the Dewey Decimal System, the Taxonomy gives information and referral systems around the country a common structure for coding human services in their communities." — Carol Davis, retired, formerly with United Way of Connecticut/2-1-1

"The AIRS/211 LA County Taxonomy is particularly helpful because of its flexibility. The six level system permits small and large organizations to index at the level best suited to their needs." — Diane Gatto Barrett, United Way 211/First Call for Help, Cleveland

"As the health and human services field changes, so does the Taxonomy. The fact that the Taxonomy includes 'see also' and 'use references' is invaluable, as they make it easier to find the correct term and explore other options while indexing your database." — Cathleen Dwyer, Consultant

"As we confront process and technological challenges of merging databases, the Taxonomy has given us a common language to talk about services. It was an easy decision for us to adopt the Taxonomy as a cornerstone of how we will provide information about services in Nebraska." — Nancy Shank, University of Nebraska Public Policy Center

"The TAXONOMY is one of a small number of critical standards for bringing the field of I&R out of the shadows. Without a standard, there is no system. And without a system, we will never have the visibility we need to fulfill our mission. I urge you to use it." — Gil Evans, Past President, AIRS Board

"The AIRS/211 LA County Taxonomy is one of the best examples of a highly detailed and precise taxonomy designed especially for information and referral (I&R) programs. We commend this taxonomy to I&R programs looking for good models."  — United Way of America

"We appreciate the Taxonomy's precise structure and carefully worded and defined individual terms. We can't imagine managing our resource database without the Taxonomy.

We've learned how to customize it to meet our own needs by deciding what level we want to index any given concept. Rather than using all of the nearly 7,000 service terms (not counting the additional 1,300 target terms), we've settled on a manageable core set of about 1,300 terms. And we use a fairly small set of target terms to focus the indexing more precisely when that's needed.

If we can't figure out how to index a concept, we post a note to the AIRS Taxonomy Listserv and invariably get useful advice from other users. If it turns out that no appropriate Taxonomy term exists, one generally gets created and shared with us.

When new updates are released to subscribers, we run a special utility that our software developer created to integrate new and changed terms into the Taxonomy embedded in our resource database.

Best of all, we can focus our attention on keeping our resource data accurate and up-to-date rather than on maintaining the Taxonomy.

Life is good for us with the AIRS/211 LA County Taxonomy!" — Dick Manikowski, retired, formerly with the Detroit Public Library - TIP Service

NOTE: Portions of this site and the Taxonomy can be accessed for limited use without an account. Please see the links at the top of this page and the Terms of Use for further information.

Privacy Policy. Terms of Use. Contact 211 LA County.

Thank you for your interest in obtaining or renewing your 211 HSIS taxonomy subscription

211 LA is preparing to launch delivery of the 211 Human Services Indexing System (HSIS) (formerly the 211 LA Taxonomy) via an API. The API will enable licensed vendors and licensed users to receive real time updates to the HSIS taxonomy. As part of the transition to delivery via API, the current process of providing an XML download will be retired in January 2024. 211 LA is working with its licensed vendors to enable integration of the API within their applications. We are targeting to have our licensed vendor transition completed by January 2024.

The 211 HSIS website is also being updated. The updates will continue to support the existing filtering functionality and “how-to” guides you enjoy today as well as additional features including enhanced search functionality.

Below is a table summarizing the new subscription tiers related to the Website and HSIS taxonomy:

Below is a table describing some common user situations and highlights the considerations for and impact on your organization with respect to desired functionality and 211 HSIS access.

SituationWhat it means for my organization
Current Subscriber who uses a licensed vendor or does not need to download the XML file
  • You will can renew your subscription at the subscription rates shown above:
  • Your subscription will enable continued use of the HSIS taxonomy through your licensed vendor but you will not be able to download the HSIS taxonomy via XML or PDF as that functionality will be discontinued
  • Once the new Website is available there will be a new online agreement we will ask subscribers to acknowledge
New Subscriber who uses a licensed vendor or does not need to download the XML file
  • You can establish your new subscription at the subscription rates shown above:
  • Your subscription will enable use of the HSIS taxonomy through your licensed vendor but you will not be able to download the taxonomy via XML or PDF as that functionality will be discontinued
  • Once the new Website is available there will be a new online agreement we will ask subscribers to acknowledge
Current or New Subscriber who need access to the HSIS taxonomy and do not/will not use a licensed vendor
  • You will need to become a licensed user to enable access to the HSIS taxonomy API
  • You will need to sign an HSIS taxonomy agreement
  • You will need to integrate your application with the HSIS taxonomy API

  • If you would like access to the HSIS taxonomy sandbox to assist in your development activities, please send your request to the email below to initiate the process to complete a sandbox agreement and provide access to the developer tools:
  • As a licensed user, you will have full access to the Website functionality including access to the APIs
  • If your organization is a 211, Area Agency on Aging (AAA) or a Crisis Line, please reach out to 211 LA at the above email and we can work together on the path to becoming a Licensed User including access to the Sandbox and Production API.

Check out our FAQ on Subscriber API Activity here.

If you have any questions regarding the HSIS taxonomy API and the ongoing transition, please send an email to:


We will continue to provide updates and information regarding the HSIS taxonomy as the transition plans and materials are finalized.

Thank you for your continued support and use of the HSIS taxonomy within the I&R community!!

The 211 HSIS Team