IBM Medicare Via Benefits part D structure 2020 & Kaiser Foundation & Medicare part D brochure information

In January 2020 the "doughnut hole" closes for generic drugs.
 
That means that in the second stage of drug plans, you will pay a 25% copay for the negotiated price of your drugs.  That might be more or less than you pay in the first phase.  The terminology for the second phase of "doughnut hole" has no meaning.  It started with there being NO coverage in the second phase in 2006 and that condition has gradually been remedied to where the second phase now provides policy holders with part D co-insurance coverage that approximates the first phase.
   
The pharmaceutical companies must still absorb the rest of the cost of the drug cost in the second phase.  For brand name drugs, they are not likely to do much negotiation with the insurance carrier to discount the drug because they will only be paid something less than 25% of the drug cost.  It depends on how many middlemen are involved that must also be paid.
 
There are two references in this post that will help you know more about drug plans and how they are structured.  The first, from Kaiser Foundation is a great analysis and also explains why there is such a big jump in out of pocket costs as policy holders move through the different phases.  There were provisions in the Affordable Care Act (ACA) aka ObamaCare that held down those costs.  Those provisions lapsed in 2019 and were not renewed by the current administration.
 
The second brochure is Medicare's attempt to explain the cost structure without getting too wonky.  It's a decent explanation.
 
https://www.kff.org/medicare/fact-sheet/an-overview-of-the-medicare-part-d-prescription-drug-benefit/
   
https://www.medicare.gov/Pubs/pdf/11109-Your-Guide-to-Medicare-Prescrip-Drug-Cov.pdf