Aspects of the present disclosure are directed to performing varying frequency memory sub-system background scans using either or both a timer and an I/O event limit. This can be accomplished by identifying a background scan trigger event from one of multiple possible types of background scan trigger events, such as a timer expiration or reaching an event count limit. In response to the background scan trigger event, a background scan can be initiated on a memory portion. The background scan can produce results, such as CDF-based data. When a metric based on the results exceeds a background scan limit, a refresh relocation can be performed and logged. A metric can be generated based on the CDF-based data, obtained error recovery depth data, or refresh relocation event data. When the metric is above or below corresponding background scan thresholds, a background scan frequency can be adjusted.