In the January 2022 issue of Health Affairs, Schwartz et al. study the rate of denials in Medicare Advantage, using Aetna data (most authors from CVS which acquired Aetna in November 2018). Denial rates were only about 1% and 85% of Medicare Advantage denials were rooted in Medicare fee for service policies. (Aetna can deny additional claims, when there is no Medicare policy to the contrary and when the service is deemed not beneficial by Aetna). Here.
Exhibit 3 shows that laboratory service denials swamp out all other medical service areas, which are miniscule in comparison.
|Click to enlarge.
For an article on rough-and-tumble contracting amongst MA plans, here.