Yes. It's concerned only with FBA, with the idea being that Amazon has enough inventory to spread throughout the system of FCs, so that they will be able to ship it from one close to any customer anywhere in the country.

(I'm lucky that, as a bookseller, I'm not affected by this fee. It's gotta be a nightmare for someone selling New items)

Greetings,

The fee will still apply if the FBA inventory has lower than 28 historical days of supply for both the short-term and long-term. It won't factor in FBM inventory. Let me know if you have additional questions!

- Bryce