The Relative Citation Ratio is not available for papers published in the current or prior fiscal year, since, in general, not enough time has passed for citation statistics to meaningfully accrue in that time frame. An exception is made for papers with five or more citations since publication, as these are deemed to be accruing citations quickly enough for reliable calculations. The current year in the database changes with the NIH Fiscal Year every October. For example, in June 2023 (NIH Fiscal Year 2023), papers from 2022 receive provisional RCRs if they have five citations or more, and all papers from 2021 receive provisional RCRs. In October 2023 (the start of NIH Fiscal Year 2024), papers from 2023 receive provisional RCRs if they have five citations or more, and all papers from 2022 receive provisional RCRs.
The citation database powering iCite is generated from a number of sources, including CrossRef, MedLine, PubMed Central, and Entrez. At present, only PubMed citations are included, so citations appearing from journals outside PubMed are not counted.