AttorneyGrant said:

They are two different exemptions from the same federal requirements and they buy different things.

Compounding pharmacy response time test for compounded supply: I email customer service at odd hours to test responsiveness. A pharmacy that can't answer questions promptly is a red flag.

My current pharmacy: average response time same day. They answered my questions about sterility testing thoroughly and professionally.

Communication quality is a proxy for operational quality. A pharmacy that communicates well is likely manufacturing well too.

One thing that is still open after DeniseRN_TPA’s answer:

Why a shortage listing created a legal pathway at all, since a shortage is a supply fact rather than a permission?

PeptideSynthNJ said:

Compounding pharmacy response time test for compounded supply: I email customer service at odd hours to test responsiveness.

503A vs 503B compounding pharmacies for compounded supply — this distinction matters enormously:

I strongly recommend 503B facilities. The FDA oversight and cGMP requirements mean more consistent product quality.

Closing the loop on my own question.

The bulks-list asymmetry was the piece I had missed entirely. It explains why one of my two pharmacies is still arguing it can supply and the other simply stopped.

traveltech_sara said:

503A vs 503B compounding pharmacies for compounded supply — this distinction matters enormously: Feature 503A 503B Regulation State Board of Pharmacy…

Agreed, and the enforcement dates were staggered by category — 503A first, 503B a few weeks later — because outsourcing facilities have manufactured inventory and clinic contracts to unwind while a 503A makes to order.