The Iron Cutoff Was Set Too Low. It Just Went Up.

What the new ASH guidelines change, and the number to ask for.

On September 16, 2026, the American Society of Hematology (ASH) released its first evidence-based guidelines for diagnosing iron deficiency. The short version: the ferritin level that counts as "too low" just went up (Powers et al., 2026).

That matters more than it sounds. For years, your bloodwork could come back "normal" while your iron stores sat near empty. The old number wasn't catching people. The new one is built to.

What actually changed

Iron deficiency is usually diagnosed with a blood test for ferritin, the protein that stores iron. Below a set number, you're considered deficient. ASH raised that number across the board (American Society of Hematology, 2026; Powers et al., 2026):

1. Adults, and people who are menstruating or pregnant: ferritin of 30 ng/mL or lower. The old common cutoff was 15.
2. Children aged 9 months to 4 years: 20 ng/mL or lower. It was 12.
3. Higher-risk situations, including ...

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