OK, the title might be clickbait. It's a Palmetto LCD, and a lab LCD, but it's not a MolDx LCD.
On September 1, 2022, Palmetto posted an LCD for measurement of serum magnesium, comments ending October 15, 2022. No comments were received. The draft LCD was posted as a final LCD on December 8, 2022.
That's just over 90 days from posted draft LCD to posted final.
It's one of Palmetto's few LCDs that has a concise one-word title:
The code for magnesium is 83735. About 5,000 ICD10 codes are covered under the billing article, which is 168 pages long. Such as, T20.612A, corrosion of second degree of right ear, any part, except eardrum, and T47.95XD, adverse effect of unspecified agents affecting the GI system (when ordered in subsequent, not initial, encounter.)
National payments in 2021 were about $22M (for 3M services, or about $7 a pop), which is about 50 cents per Medicare beneficiary.
In 2020, almost 7000 different entities (labs, docs) billed Medicare for magnesium testing, but just 25 labs billing more than $150,000 garnered 37% of all payments. Those large entities were almost all regional billing locations for Quest and Labcorp.
Labcorp billed Medicare under about 90 different NPIs (locations) for 83735, ranging from $1M from Burlington NC, down to $80 from a Labcorp location on New Street in Greensboro NC. CMS reports that Labcorp charges, per location, per test, ranged from $59 down to $22 (median $37).
The pre-PAMA price of 83735 Magnesium was $9.19; the PAMA weighted median was $6.12, down 33%.