Reticulocyte % levels: what's normal, high and low
The percentage of red blood cells that are immature (newly produced).
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
The short answer
Reticulocyte % is measured with a standard blood draw; no fasting is needed. A typical reference range is 0.500 – 2.50 %. TestWell offers panels that include Reticulocyte %, drawn at Quest or Labcorp. An out-of-range result is a prompt to look closer, not a diagnosis.
Find a Reticulocyte % test
We offer panels that include this marker. Browse to find the best fit.
Browse tests- Units
- %
- Sample
- Blood
- Fasting
- Not required
- Results
- 1–3 business days
- Labs
- Quest or Labcorp
Reticulocyte % Reference Range
These are the typical adult reference ranges used by major US labs. Your report will include the specific range used by the lab that processed your sample.
| Population | Range |
|---|---|
| age 18+ | 0.500 – 2.50 % |
Reference ranges are educational. Always interpret your result with the specific range printed on your lab report and discuss anything outside the range with a clinician.
Related Blood Health biomarkers
Markers commonly tested alongside Reticulocyte %.
Frequently asked
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