A '**' entry in 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.
A '-' entry in the estimate column indicates that 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.
A '-' following a median estimate means the median falls in the lowest interval of an open-ended distribution.
A '+' following a median estimate means the median falls in the upper interval of an open-ended distribution.
A '***' entry in the margin of error column indicates that the median falls in the lowest interval or upper interval of an open-ended distribution. A statistical test is not appropriate.
A '*****' entry in the margin of error column indicates that the estimate is controlled. A statistical test for sampling variability is not appropriate.
An 'N' entry in the estimate and margin of error columns indicates that data for this geographic area cannot be displayed because the number of sample cases is too small.
An '(X)' means that the estimate is not applicable or not available.
An * indicates that the estimate is significantly different (at a 90% confidence level) than the estimate from the most current year. A "c" indicates the estimates for that year and the current year are both controlled; a statistical test is not appropriate.

Notes on Annotation Values and Variable Endings

ACS 1-Year Data contain variables ending in E, EA, M, MA, PE, PM and SS. See the table below for each variable type and its meaning:

Variable Type	Title	Related Products	Meaning
E	Estimate	Summary Files, Subject Tables, Data Profiles, Comparison Profiles	A numeric representation of the estimate.
EA	Estimate Annotation	Subject Tables, Comparison Profiles	A character representation of the estimate. If an Estimate Annotation exists, use this value in place of the Estimate. (See Example #1 below)
M	Margin of Error	Summary Files, Subject Tables, Data Profiles	A numeric representation of the margin of error.
MA	Margin of Error Annotation	Subject Tables Only	A character representation of the margin of error. If a Margin of Error Annotation exists, use this value in place of the Margin of Error.
PE	Percent Estimate	Data Profiles Only	An estimate representing a percent of the total.
PM	Percent Margin of Error	Data Profiles Only	The Margin of Error for the corresponding Percent Estimate (PE) variable
SS	Statistical Significance	Comparison Profiles Only	Returns ‘’ or ‘c’ representing the Statistical Significance for the corresponding estimate (E) variable. (See Example #2 below) An indicates that the estimate is significantly different (at a 90% confidence level) than the estimate from the most current year. A "c" indicates the estimates for that year and the current year are both controlled; a statistical test is not appropriate.

Example #1: Estimate Annotations

Figure 5: Visual Representation of ACS 2015 1-Year variable S0101_C02_031E/A from Explore Census Data

Figure 1: Visual Representation of S0101_C02_031E/A from American Factfinder

In the following example, the variable S0101_C02_031EA returns “(X)”. Using the notes above, this indicates that the estimate is not applicable or not available. Since S0101_C02_031E represents the Sex Ratio (males per 100 females) and the column is for Males only this estimate is not applicable. S0101_C02_031E returns -888888888 as a caution not to use this estimate in reporting or further calculations. See Figure 1 above for a visual context for this estimate.

api.census.gov/data/2015/acs1/subject?get=NAME,S0101_C02_031E,S0101_C02_031EA,S0101_C02_031M,S0101_C02_031MA&for=us:*

Returns:

[["NAME","S0101_C02_031E","S0101_C02_031EA","S0101_C02_031M","S0101_C02_031MA","us"],

["United States","-888888888","(X)","-888888888","(X)","1"]]

Example #2: Statistical Significance

Figure 6: Visual Representation of ACS 2015 1-Year variable CP02_2015to2014_001SS from Explore Census Data

Figure 2: Visual Representation of CP02_2015to2014_001SS from American Factfinder

In the following example, the variable CP02_2015to2014_001SS returns “*”. Using the notes above, this indicates that the 2015 estimate for Total households is significantly different when compared to the 2014 estimate.

api.census.gov/data/2015/acs1/cprofile?get=NAME,CP02_2015_001E,CP02_2014_001E,CP02_2015to2014_001SS&for=us:*

Returns:

[["NAME","CP02_2015_001E","CP02_2014_001E","CP02_2015to2014_001SS","us"],

["United States","118208250","117259427","*","1"]]

More on Annotation Values

See the table below for a list of common Estimate/Margin of Error (E/M) values and their corresponding Annotation (EA/MA) values. See section above titled “Notes on ACS 1 Year Data” for Annotation Values and its meanings.