ASH Sets New Ferritin Thresholds for Iron Deficiency

Published September 18, 2026, after the American Society of Hematology released new diagnostic guidance for iron deficiency.

The American Society of Hematology, or ASH, has published new clinical practice guidelines for diagnosing iron deficiency. The guideline appeared in Blood Advances on September 16 and gives separate serum ferritin thresholds for children, adults, pregnancy, heavy menstrual bleeding, and adults with inflammation.

The new ferritin thresholds

ASH's release lists the following diagnostic thresholds:

- Children ages 9 months through 4 years: ferritin of 20 ng/mL or lower. - Adults, including menstruating or pregnant individuals: ferritin of 30 ng/mL or lower. - Higher-risk groups, including people with heavy menstrual bleeding and pregnant people with anemia: ferritin of 50 ng/mL or lower. - Adults with inflammation, including cancer, inflammatory bowel disease, or infectious disease: ferritin under 100 ng/mL or transferrin saturation under 20%.

The last criterion is an either-or standard. ASH's release says ferritin under 100 ng/mL *or* transferrin saturation under 20%, not that both findings have to be present.

ASH said the guidance addresses inconsistent diagnostic thresholds and clinical situations in which iron deficiency can be hard to identify. Guideline chair Jacquelyn M. Powers, MD, MS, called the update "clear guidance in an area where consensus has been lacking."

What the thresholds do and do not say

These are population-specific diagnostic criteria in a clinical guideline. They are not personal target values, and they do not mean that every laboratory report will use the same reference interval. A result still has to be interpreted in the context of the reporting laboratory, the person's health history, symptoms, and other findings.

The inflammation category is intentionally different from the general adult threshold. The release presents ferritin and transferrin saturation as alternatives in that setting. That distinction matters because changing "or" to "and" would make the published criterion more restrictive than ASH stated.

The guideline concerns diagnosis. It does not, by itself, tell an individual whether to start iron supplements, how much to take, or how often to repeat testing. ASH said additional guidance on treatment is expected in 2027.

Where ferritin and iron-panel testing fit

Ferritin is a protein that stores iron. A ferritin test measures the amount of ferritin in blood and can help assess iron stores. LabTestSuperstore's iron panel includes ferritin, serum iron, and total iron-binding capacity, or TIBC.

Those pages explain what the tests measure. The new ASH thresholds add context for how clinicians may diagnose iron deficiency, but they do not replace a laboratory's report or a clinician's evaluation. They also do not establish a universal reason or schedule for ordering either test.

What was verified

The threshold summary above was checked against ASH's official September 16 release. Crossref confirms the guideline record as "American Society of Hematology 2026 guidelines for diagnosis of iron deficiency," published in Blood Advances on September 16, 2026, with Jacquelyn M. Powers as first author and DOI 10.1182/bloodadvances.2025015950.

The full guideline manuscript was not independently reviewed for this article. The article therefore reports the thresholds and context stated in ASH's release without making additional claims about the guideline's methods or evidence grading.

The defensible takeaway is narrow: ASH has set higher, population-specific ferritin thresholds for diagnosing iron deficiency and a separate either-or criterion for adults with inflammation. The guidance may change how some results are interpreted, but it is not a stand-alone diagnosis or treatment instruction.

This article is editorial commentary and is not medical advice. It has not been reviewed by a physician and should not be used to diagnose iron deficiency or make individual decisions about testing, supplements, or treatment.