ACS Health Insurance Coverage Variables - Tract

This layer shows health insurance coverage by type and by age group. This is shown by tract, county, and state centroids. This service is updated annually to contain the most currently released American Community Survey (ACS) 5-year data, and contains estimates and margins of error. There are also additional calculated attributes related to this topic, which can be mapped or used within analysis. This layer is symbolized to show the count and percent uninsured. To see the full list of attributes available in this service, go to the "Data" tab, and choose "Fields" at the top right. Current Vintage: 2015-2019 ACS Table(s): B27010 (Not all lines of this ACS table are available in this feature layer.) Data downloaded from: Census Bureau's API for American Community Survey Date of API call: December 10, 2020 National Figures: data.census.gov The United States Census Bureau's American Community Survey (ACS): About the Survey Geography & ACS Technical Documentation News & Updates This ready-to-use layer can be used within ArcGIS Pro, ArcGIS Online, its configurable apps, dashboards, Story Maps, custom apps, and mobile apps. Data can also be exported for offline workflows. For more information about ACS layers, visit the FAQ. Please cite the Census and ACS when using this data. Data Note from the Census: Data are based on a sample and are subject to sampling variability. The degree of uncertainty for an estimate arising from sampling variability is represented through the use of a margin of error. The value shown here is the 90 percent margin of error. The margin of error can be interpreted as providing a 90 percent probability that the interval defined by the estimate minus the margin of error and the estimate plus the margin of error (the lower and upper confidence bounds) contains the true value. In addition to sampling variability, the ACS estimates are subject to nonsampling error (for a discussion of nonsampling variability, see Accuracy of the Data). The effect of nonsampling error is not represented in these tables. Data Processing Notes: This layer is updated automatically when the most current vintage of ACS data is released each year, usually in December. The layer always contains the latest available ACS 5-year estimates. It is updated annually within days of the Census Bureau's release schedule. Click here to learn more about ACS data releases. Boundaries come from the US Census TIGER geodatabases. Boundaries are updated at the same time as the data updates (annually), and the boundary vintage appropriately matches the data vintage as specified by the Census. These are Census boundaries with water and/or coastlines clipped for cartographic purposes. For census tracts, the water cutouts are derived from a subset of the 2010 AWATER (Area Water) boundaries offered by TIGER. For state and county boundaries, the water and coastlines are derived from the coastlines of the 500k TIGER Cartographic Boundary Shapefiles. The original AWATER and ALAND fields are still available as attributes within the data table (units are square meters). The States layer contains 52 records - all US states, Washington D.C., and Puerto Rico Census tracts with no population that occur in areas of water, such as oceans, are removed from this data service (Census Tracts beginning with 99). Percentages and derived counts, and associated margins of error, are calculated values (that can be identified by the "_calc_" stub in the field name), and abide by the specifications defined by the American Community Survey. Field alias names were created based on the Table Shells file available from the American Community Survey Summary File Documentation page. Negative values (e.g., -4444...) have been set to null, with the exception of -5555... which has been set to zero. These negative values exist in the raw API data to indicate the following situations: The margin of error column indicates that either no sample observations or too few sample observations were available to compute a standard error and thus the margin of error. A statistical test is not appropriate. Either no sample observations or too few sample observations were available to compute an estimate, or a ratio of medians cannot be calculated because one or both of the median estimates falls in the lowest interval or upper interval of an open-ended distribution. The median falls in the lowest interval of an open-ended distribution, or in the upper interval of an open-ended distribution. A statistical test is not appropriate. The estimate is controlled. A statistical test for sampling variability is not appropriate. The data for this geographic area cannot be displayed because the number of sample cases is too small.

本图层按保险类型与年龄组划分展示医疗保险覆盖情况，数据以普查区、县及州质心为统计单元呈现。本服务每年更新一次，纳入最新发布的美国社区调查（American Community Survey, ACS）5年期数据，包含统计估计值与误差边际。此外还包含与该主题相关的衍生计算属性，可用于制图或分析工作。

本图层采用符号化方式展示未参保人数与未参保占比。如需查看本服务中所有可用属性列表，请进入「数据」选项卡，并点击右上角的「字段」选项。

当前数据版本：2015-2019年ACS表项：B27010（本要素图层未包含该ACS表的全部行数据）。

数据来源：美国人口普查局美国社区调查应用程序编程接口（API）。
API调用日期：2020年12月10日。
全国统计数据：data.census.gov。

美国人口普查局美国社区调查（ACS）：调查简介、地理信息与ACS技术文档、新闻与更新。

本预制图层可在ArcGIS Pro、ArcGIS Online、其可配置应用程序、仪表盘、故事地图（Story Maps）、自定义应用及移动应用中使用。数据亦可导出用于离线工作流。如需了解更多ACS图层相关信息，请查阅常见问题解答（FAQ）。使用本数据时，请注明引用美国人口普查局与ACS。

普查局数据说明：
本数据基于抽样调查，存在抽样变异性。由抽样变异性导致的估计值不确定程度通过误差边际体现。此处展示的为90%置信度的误差边际，其含义为：估计值减去误差边际与估计值加上误差边际所构成的区间（即置信上下限）有90%的概率包含真实数值。除抽样变异性外，ACS估计值还存在非抽样误差（关于非抽样变异性的讨论，请参见《数据准确性》文档）。本表格未体现非抽样误差的影响。

数据处理说明：
本图层会在每年ACS最新版本数据发布时自动更新，通常更新时间为12月。本图层始终包含最新可用的ACS 5年期估计值，每年会在美国人口普查局发布数据后的数日内完成更新。点击此处可了解更多ACS数据发布相关信息。
地理边界数据源自美国人口普查局TIGER地理数据库。边界数据会与数据同步每年更新，且边界版本与普查局指定的数据版本完全匹配。为满足制图需求，已裁剪掉普查区、县及州边界中的水体及海岸线部分：其中普查区的水体裁剪范围源自TIGER提供的2010年AWATER（水域面积）边界子集；州与县级边界的水体及海岸线则源自50万比例尺TIGER制图边界形状文件的海岸线数据。
数据表格中仍保留原始AWATER与ALAND字段（单位：平方米）。本州级图层包含52条记录，涵盖美国所有州、哥伦比亚特区及波多黎各。
本数据服务已移除水域区域（如海洋）内无人口的普查区（即编码以99开头的普查区）。
百分比与衍生计数及其对应的误差边际均为计算所得值（可通过字段名中的「_calc_」前缀识别），且符合ACS的相关规范。字段别名名称基于ACS汇总文件文档页面提供的表壳文件生成。
除-5555…这类数值已被置为0外，其余负值（如-4444…）均已被置为空值。原始API数据中的这类负值用于指示以下情形：
1. 误差边际列表明：无可用抽样观测值或抽样观测值过少，无法计算标准误，进而无法计算误差边际，此时不适合进行统计检验；
2. 无可用抽样观测值或抽样观测值过少，无法计算估计值；或因其中一个或两个中位数估计值落在开放式分布的最低区间或最高区间，无法计算中位数比率；
3. 中位数落在开放式分布的最低区间或最高区间；
4. 不适合进行统计检验；
5. 估计值已受控，不适合进行抽样变异性统计检验；
6. 因抽样案例数量过少，无法展示该地理区域的数据。