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Key Terms

The following are key terms and definitions of important concepts to understanding and engaging with the AARP Livability Index.


Accessibility refers to community services, features, and amenities that take into account varying levels of physical mobility


Affordability refers to features, services and amenities that are suitable for people at different levels of income.

Age-Friendly Communities

An age-friendly community supports and meets the needs of people of all ages.

The AARP Network of Age-Friendly States and Communities serves as a catalyst to educate local leaders (both elected officials and engaged residents) and encourage them to implement the types of changes that make communities more livable, especially older adults.

Learn More and Join the Network


Attributes refer to qualities or features regarded as a characteristic of a livable community. Examples of this include affordability, accessibility, safety, convenience, inclusion, prevention, quality, resilience and involvement.


Categories refer to general topic areas that define the type of characteristics found within a community. AARP selected 7 livability categories that are critical to evaluating a community. They are: housing, neighborhood, transportation, environment, health, engagement, and opportunity. These categories are scored on a scale of 0-100 and each receive weight.

Learn more about the 7 AARP Livability Index Categories and understand how they impact the overall score.

Commitment To Livability

“Commitment to livability” is a cross-cutting policy that refers to membership in the Network of Age Friendly States and Communities. This policy appears under each category, contributing one point to the total score.


A community refers to a town, city or larger collective of smaller neighborhoods.


The General Transit Feed Specification (GTFS) is the de facto data standard for public transit passenger information. The GTFS allows transportation service providers to share their geographic, schedule, fare and other data with traveler-facing applications, such as Google Maps, to aid customers with trip planning.

Imputed Data

Imputed data is an estimated value where actual data for that location is unavailable.

AARP imputes missing data by assigning estimated values in two ways:

  • We may use the national average, which results in a neutral performance on an indicator.
  • We may assign the state or rural average if that appears to be more accurate than the national average.


There is no one definition of livability—it means different things to different people. Communities that are truly livable offer diverse features that appeal to people of all ages, incomes, and abilities.

AARP determines livability by evaluating how a community supports its members in seven critical categories: housing, neighborhood, transportation, environment, health, engagement, and opportunity.

Take a deeper dive into Livability


Metrics measure how livable communities are in the present. Each livability category contains 4-9 metrics and data is collected and analyzed from local, state, federal, and private sources.

Discover the metrics AARP uses for the AARP Livability Index and understand how they impact the overall score.

Missing Middle Housing

Missing middle housing describes a range of multifamily housing types that are compatible in scale with detached single-family homes (e.g., duplex, fourplex, townhouse).


A neighborhood refers to a census block group. Scores are built from the neighborhood level (census block group) up, a community is scored on the collective neighborhood scores within their boundaries.


Policies measure actions that communities can take now to improve livability over time. Each livability category contains 1-5 policies and policy data is publicly available and covers the entire US.

Discover the policies AARP uses for the AARP Livability Index and understand how they impact the overall score.