TOOLS: MetaMap

What's New in MetaMap?

May 2020 - MetaMap 2020 Release

More information on these changes are described in the Release Notes for MetaMap 2020 (PDF)

December 2018 - MetaMap 2018 Release

More information on these changes are described in the Release Notes for MetaMap 2018 (PDF)

September 2016 - MetaMap 2016v2 Release

See FAQ for more information on 2016v2 enhancements.

More information on these changes are described in the Release Notes for MetaMap 2016v2 (PDF)

February 2016 - MetaMap 2016 Release

MetaMap 2016 includes the much-requested and long-awaited functionality of ad-hoc exclusions of unwanted results, a new FAQ, and a utility program for converting UTF-8 to ASCII.

More information on these changes are described in the Release Notes for MetaMap16.

August 2014 - MetaMap 2014 Release

MetaMap 2014 includes several enhancements including improvements to WSD Server Efficiency, Changes in the default display of human, machine, XML, and Fielded MMI output formats, the addition of a MetaMap specific Subsynonymy vocabulary, and user-definable NegEx negation triggers.

More information on these changes are described in the Release Notes for MetaMap14.

September 2013 - MetaMap 2013 Release

MetaMap 2013 includes several interesting user-driven enhancements including modifications to our NegEx implementation, and an adjustable blank lines feature.

Important Note: MetaMap 2013 relies on a new Berkeley-DB table that does not exist in previously downloaded datasets (2012AA, 2012AB, etc.), so we strongly encourage using the 2013AA data with MetaMap 2013. In order to ensure backward compatibility with previous datasets, however, we have added a version of that table to all pre-2013 datasets, which are available at the Additional Datasets section of this page. Users needing to run MetaMap2013 with previous datasets should download and re-install them.

More information is available in the MetaMap 2013 Release Notes (pdf).

July 2012 - MetaMap 2012 Release

MetaMap 2012 is primarily a bug-fix release including the 2012AA version of the UMLS data.

May 2012 - MetaMap 2011 Version 2 Release (2011v2)

MetaMap2011v2 includes some significant enhancements, most notably revisions to the mappingconstruction algorithms that further speed the analysis of text that had remained problematic for MetaMap 2011. This release also includes improvements to the format of all MetaMap output (human readable, Prolog Machine Output, and XML), as well as two new input formats. The changes to MetaMap's output format will almost certainly require modifications to user-developed programs that postprocess MetaMap output.

These enhancements include:

  • Further Algorithmic Improvements
  • Enhancements to Exclusion and Pruning of Candidates
  • New Changes Output Formats (Human Readable, Machine, XML)
  • Single-Line Delimited Output
  • Retired Command-Line options

See the MetaMap 2011 v2 Release Notes (PDF) for more information.

October 2011 - MetaMap 2011 Release

MetaMap2011 includes some significant enhancements, most notably algorithmic improvements that enable MetaMap to very quickly process input text that had previously been computationally intractable.

These enhancements include:

  • Algorithmic Improvements
  • Candidate Set Pruning
  • Re-Organization of Additional Data Models
  • Single-character alphabetic tokens
  • Improved Treatment of Apostrophe-"s"
  • New XML Command-Line Options
  • Numbered Mappings
  • User-Defined Acronyms and Abbreviations

Starting with MetaMap 2011, MetaMap is now available for Windows XP and Windows 7.

Important Note: When using MetaMap 2011 with data sets earlier than 2011, users may experience problems when applying the --restrict_to_sources and --exclude_sources options. The Ancillary Data Files for MetaMap 2011 provide the additional files necessary to ensure proper operation of MetaMap 2011. These files are available for many pre-2011 data sets.

With the 2011 Release of MetaMap, we are retiring two previous versions of MetaMap, namely MetaMap09 and MetaMap09V2. Only the MetaMap binary executables are being retired; the MetaMap UMLS datasets corresponding to these releases (2009AA and 2009AB) will remain available.

Please see the Release Notes for more information on the MetaMap 2011 Release.

October 2010 - MetaMap 2010 Release

With the 2010 Release of MetaMap, we are retiring three previous versions of MetaMap, namely MetaMap07, MetaMap08, and MetaMap08V2. Only the MetaMap binary executables are being retired; the MetaMap UMLS datasets corresponding to these releases (2007AA, 2008AA, and 2008AB) will remain available.

MetaMap 2010 includes less new functionality than previous releases because the bulk of our development efforts since MetaMap09V2 have focused on converting MetaMap from Quintus Prolog to SICStus Prolog, which will henceforth be the principal implementation vehicle of MetaMap. We also converted MetaMap 2010 to version 4.8.24 of Berkeley DB, as recommended by SICS.

New functionality and enhancements delivered in MetaMap 2010 include the following:

  • De-Normalized Data Tables,
  • Minimum Concept Length,
  • Changes in Numerical Output Format,
  • Silent Mode, and
  • Variants Bug Fix.

Please see the Release Notes for more information.

April 2010 - UIMA Annotator

The MetaMap UIMA Annotator encodes MetaMap named entities in a format utilizable by UIMA components. The annotator is based on the MetaMap UIMA Wrapper authored by Kai Schlamp. The annotator utilizes classes from the MetaMap Java API which is required for use of the annotator.

Differences from Kai Schamp's MetaMap UIMA Wrapper include a modified UIMA type system which includes Acronyms and Abbreviations and the addition of a MatchMap structure to the Candidates and Mappings. Use of MetaMap XML and the SKR API are currently not supported.

January 2010 - MetaMap 2009 version 2 Release

This release provides an updated version of MetaMap consisting of mostly bug fixes and enhancements to our implementation of NegEx, the AA-detection logic and lexical processing.

This release includes also three more substantive changes:

  • New Phrase-Breaking Method,
  • MatchMap Consolidation, and, most significantly,
  • Improvements in XML generation.

Please see the Release Notes for more information.

December 2009 - Data File Builder Suite Release

The Data File Builder suite exists to allow end users to create custom datasets for use with MetaMap.

A MetaMap data set contains preprocessed UMLS data that MetaMap references as it maps text to concepts. The data set determines the domain of strings that MetaMap will be able to map and the range of target concepts. The Additional Datasets available for download on this site are examples of the standard data sets.

See the MetaMap Data File Builder section for information on downloading the Data File Builder release.

December 2009 - MetaMap Source Code Release

Contains the Prolog and C code and the scripts necessary to build and modify MetaMap, see MetaMap Sources Release for more information on the prerequisites required to build MetaMap.

July 30, 2009 - MetaMap 2009 Released

New in this Release

  1. NegEx enhancements,
  2. More options for XML generation,
  3. A new sentence-breaking algorithm,
  4. A new input format,
  5. Elimination of Moderate Model, and
  6. Elimination of display_original_phrases command-line option.

Other less visible changes, which will be mentioned but not described further, are various bug fixes involving the exclude_sources option, the display_original_phrase option, the term_processing option, positional information, and Fielded MMI Output. We also added several new Acronym/Abbreviation-detection rules. Finally, we upgraded MetaMap from Berkeley DB 3.0.55 to 4.1.24; this last change is completely transparent to users, but it will require keeping multiple versions of the database files if you want to run both MetaMap09 and any previous release on the same filesystem.

For more information on the changes in MetaMap since the previous release, see the MetaMap 2009 Release Notes.


Previous MetaMap databases are not compatible with this version of MetaMap. This version of MetaMap uses data indexes that have additional information within them. If you have used one of the Optional Data Models in the past, you will need to download the new versions from the MetaMap website.

Important Notes

  • A MetaMap version of DataFileBuilder software will soon be released to allow users to create their own MetaMap databases.
  • A Java-based API for MetaMap is in development to allow Java programs to access the MetaMap mapping engine.