Letters to the Editor
These are usually invited commentaries published alongside other articles. They may or may not be peer-reviewed.
Corrigenda and Addenda
This section lists all substantive corrections, additions, or changes made to articles and reviews subsequent to their first publication in the journal. The corresponding author of the original article or the section editor usually submits corrigenda. Published papers are considered "final"; thus, JMIR makes corrections to published papers only in exceptional circumstances. Note that while we do not charge to correct errata that are the responsibility of the publisher, we charge a $190 fee for discretionary corrigenda and addenda (please submit a correction under that section if it is the authors' responsibility/decision to correct or add information to an already published article).
For corrigenda that are discretionary and a result of author oversight (e.g. corrections in the affiliation), we charge a $190 processing fee to make changes in the original paper and publish an erratum. Please submit a correction statement (text similar to http://www.jmir.org/2015/3/e76/) under the section "Discretionary Corrigenda."