Data and methodology
Abortion statistics are frequently quoted without the four things that make them mean anything: what was counted, who counted it, for which year, and what was left out. This section explains those before it explains any number.
This section describes how abortion data is collected and what its limits are. It does not publish derived national totals, and it does not present figures from different sources as though they were the same measurement.
Why two credible sources publish different totals
It is common to see two national figures for the same year that do not match, and for each to be presented as though the other were wrong. Usually neither is. They are answers to different questions, produced by different methods, over different sets of jurisdictions.
The most important distinction is between a surveillance system and a survey. A surveillance system compiles what reporting areas send in. A survey goes out and asks providers directly. When participation in the first is voluntary and incomplete, the two will not agree, and the gap is not evidence of anyone hiding anything.
The rules this site follows with data
- The data year and the publication date are both shown, and they are never conflated.
- The reporting areas included are named, and the ones missing are named.
- The definition and the denominator are stated.
- Suppression and uncertainty in the source are explained rather than smoothed over.
- The exact report or dataset is linked.
- Residence and occurrence are distinguished.
- Datasets from different sources are never combined without a methodology note.
- Original units are preserved, and any transformation is documented.
- Government data is never presented as though this site produced it.
- Every chart has a prose summary and an accessible data table with the same numbers.
- Numbers are never animated, and a figure is never called current because the site was rebuilt.
The CDC publishes an annual Abortion Surveillance report. It compiles what reporting areas voluntarily send in, which makes it a surveillance system rather than a complete national census. This table sets out the questions worth asking of any figure taken from it.
| Question to ask of any figure | What CDC abortion surveillance answers |
|---|---|
| What is being counted | Abortions reported to a reporting area by the providers and facilities within it. |
| Who reports | Central health agencies in participating reporting areas, which are the states, the District of Columbia, and New York City. |
| Is reporting required | No. Reporting to the CDC is voluntary, so participation is not guaranteed and it is not uniform. |
| Do all jurisdictions take part | No. Some do not report, and which ones report has changed between years. |
| Whose abortions appear in a state total | This depends on whether the figure is by residence or by occurrence. Those are different questions and they give different answers. |
| Is the data year the same as the publication year | No. The report for a given data year is published later, and confusing the two is the most common error in coverage. |
| Can totals be compared with other sources | Not directly. Independent survey estimates use different methods and different definitions, so the two are not interchangeable. |
- Data year
- 2022, in the report published on November 27, 2024
- Method
- Compiled from the CDC's own description of its surveillance system and the methods section of its annual report. No figures are reproduced here and none are derived.
- Limitations
- Reporting to the CDC is voluntary. Participation differs between years and some jurisdictions do not report at all. Totals are therefore not a complete national count and are not directly comparable with independent survey estimates.
- Source
- CDC Abortion Surveillance System frequently asked questions (opens www.cdc.gov)
Read the sources directly
Centers for Disease Control and Prevention, Abortion Surveillance, United States, 2022 (opens www.cdc.gov). The report itself, including its methods section and the list of reporting areas.
Centers for Disease Control and Prevention, Abortion Surveillance System (opens www.cdc.gov). How the system works, what it defines, and what it does not capture.
What is not here yet
This section does not yet publish derived charts, trend analysis, or a coverage map. Those are planned, and they will arrive with their methodology, their versioned data files, and their limitations rather than as pictures with a caption.
If you are writing about this data and something on this page is wrong or incomplete, the corrections process is the fastest route to fixing it.