Relative Citation Ratio is not available for papers published in the current or last 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 5 or more citations since publication, as these are deemed to be accruing citations quickly enough for reliable calculations.
RCRs for papers published two years ago are flagged as "provisional" to reflect that citation metrics for newer articles are not necessarily as stable as they are for older articles. The current year in the database increments with the NIH Fiscal Year every October. For example, in June 2026 (NIH Fiscal Year 2019), papers from 2025 or 2026 receive provisional RCRs if they have 5 citations or more, and all papers from 2024 receive provisional RCRs. In October 2026 (the start of NIH Fiscal Year 2027), papers from 2026 receive provisional RCRs if they have 5 citations or more, and all papers from 2025 receive provisional RCRs.