Names Methodology

How does DueDateLab decide what a baby-name page can say? This methodology explains the SSA-only source policy, suppression handling, sex-series labelling, tabulation rules, and limits behind every name page on the site.

What this methodology covers

DueDateLab name pages report popularity and historical trend data only. Each page shows where a name sits in the most recent SSA national ranking, how often it has been recorded over time, peak and recent trend information, and related names selected under the rules below. The pages do not report meanings, etymological origins, pronunciation guidance, religious or ethnic classification, “famous people named X” lists, or invented personality descriptions. Those topics are not included because DueDateLab has not approved a licensed, reliable source for that material.

Source of record

Popularity data comes from Social Security card applications for U.S. births, published by the U.S. Social Security Administration. DueDateLab uses the downloadable SSA national data file, not third-party baby-name datasets and not the top-1000 form output alone. The public SSA file reports name, year of birth, sex, and count; hyphens and spaces are removed before names are counted. Each name page is bound to a specific SSA release year and to the direct SSA data file by SHA-256 hash, so the data on the page can be reproduced from the source.

Source: U.S. Social Security Administration baby-name data. Counts are based on Social Security card applications for U.S. births and the sex recorded on the application. The public files exclude names when publication would indicate, or allow determination of, fewer than 5 occurrences in any geographic area. Names absent from the public file are shown as “not reported in SSA public data,” not zero.

Name-page eligibility

A name is eligible for a DueDateLab page only if it appears in the SSA national public data file for the release year used by the page and passes an editorial eligibility filter for name pages. DueDateLab does not publish pages for obvious placeholders, non-name terms, titles, or surname-only terms. Because SSA does not remove entries such as “Unknown” and “Baby” from its lists, this filter affects which pages are created; it does not change the SSA counts shown for eligible names.

Geographic scope

DueDateLab uses SSA national U.S. data only. SSA national name data is restricted to births in the 50 states and District of Columbia. Territory data is published separately and is not included in the national file. State-specific and territory-specific breakdowns are out of scope.

SSA suppression rules

The public SSA files exclude names when publication would indicate, or allow determination of, fewer than 5 occurrences in any geographic area. When a name has no public row for a year, the public data does not distinguish between no recorded uses and a count suppressed under that privacy rule. DueDateLab pages therefore show “not reported in SSA public data for this year,” never zero, and never a year-specific claim of “fewer than 5.” This rule applies to both rank and count fields.

Sex-series labelling

Counts are grouped by the sex recorded on the Social Security card application, not by gender identity, gender expression, or any later legal sex change. DueDateLab pages mirror that exactly. A name that has been historically recorded under both sex categories receives both series, and each series is labelled “based on the sex recorded on the application.” Pages do not make identity claims, and they do not collapse the two series into a single “unisex” total. The reader can see both series side by side and decide what to do with that information.

How SSA tabulates hyphenated and spaced names

In SSA tabulation, hyphens and spaces are removed before names are counted. That means “Mary-Jane,” “Mary Jane,” and “Maryjane” are counted together under a single SSA entry, even though many parents consider these distinct names. DueDateLab name pages explain this where a spelling, hyphen, space, or compound form could affect reader expectations.

“Not reported” handling

When a name is absent from SSA’s public file for a year, the page shows the year on the timeline with the label “not reported in SSA public data for this year.” It does not show zero, it does not show “fewer than five” as a year-specific number, and it does not interpolate between adjacent years. The line chart on each page draws a gap, not a flat line, on suppressed years. This is the most accurate way to display the underlying source given SSA’s stated suppression rule.

Rank versus count

Each page reports both the SSA rank and the absolute count for the most recent release year and historically. Rank is sex-specific within the SSA file, so a name’s rank cannot be compared across the male and female series in a way that suggests a single unified popularity ladder. Count is a raw integer of recorded applications. DueDateLab does not compute a percent-of-births figure because the SSA suppression rule means a naive sum of the public file undercounts the true denominator, and we will not publish a figure we cannot defend mathematically.

Trend summaries

Trend summaries report only values calculated from the name’s SSA series: peak year and peak rank, recent multi-year direction (rising, falling, or stable based on a simple slope test on the most recent five reported years), and first or last appearance in the public file. The summary states the data pattern without adding causal or cultural explanations. If the reader wants a cultural read on a trend, that is a separate editorial product and not what these pages provide.

Related names

Each page lists up to ten related names. The list is built from two SSA-only rules: (1) names that share the first three or four letters and appear in the same SSA sex series in the most recent release year, and (2) names that appear adjacently in rank within the same SSA sex series and release year. Related-name lists are not seeded from third-party baby-name sites. The page footer documents which of the two rules produced each suggestion.

Refresh cadence

DueDateLab checks the SSA baby-name page and downloadable national data file each May. When SSA publishes a new release, DueDateLab refreshes name pages within four weeks. The release year used to generate a page is shown in the source note on the page, so a reader can see whether the page reflects the most recent release. Pages built from older releases are not silently overwritten; the source note carries the historical release year until the page is regenerated.

What the page does not include

DueDateLab name pages do not include name meanings, etymological origins, pronunciation guides, recorded audio, religious or ethnic classification, gender-identity claims, lists of famous people, AI-generated personality descriptions, or curated nickname suggestions. These topics raise either licensing questions, because etymology and meaning data is often held by commercial dictionaries and share-alike encyclopedias, or editorial-quality questions, because personality and famous-person content can invite unverifiable claims. If a name page adds any of these topics later, the methodology will be updated and the page will declare which licensed source provided the material.

Schema and structured data

Name pages use the WebPage and BreadcrumbList schemas. They do not use the Person schema, because the page is about a name’s recorded popularity, not about an individual. They do not use the Dataset schema, because the page surfaces SSA data through narrative, charts, and a small results block, not as a downloadable dataset. The methodology page itself, which you are reading now, also uses WebPage + BreadcrumbList.

Privacy of page interactions

Name pages do not accept user input. There is no calculator on a name page, no name-search form that submits data to a server, and no behaviour that is conditioned on a logged-in identity. Page-level analytics are covered by the privacy policy. The pages collect no name search data because no name search exists on these pages.

Sources

Methodology change log

Authorship

The DueDateLab Editorial team writes and maintains this page. DueDateLab is published from Belgium. Every claim about how SSA data is structured is bound to the SSA’s own published documentation, linked above. If a future SSA documentation update changes the rules described on this page, the page will be revised within four weeks and the change documented in the methodology change log.

Conflicts of interest. DueDateLab is supported by advertising and may use affiliate links. Advertising and affiliate relationships do not influence the methodology, sources, or data handling described on this page. Any sponsored content is clearly labelled.

Last updated May 15, 2026.