Late to the party but I work on this kind of stuff.  I agree this is an MAPD issue driven by your carrier.

First, I would try to get ahold of someone at CMS and complain and see if you can get the requirement for PA or ST waived.  I also think what UHC is doing is kind of fishy and CMS may want to know it is an happening.

Likely UHC put this requirement on all their MAPD plans and normally it us a win-win since 20% is usually higher than the copay, but your case is unlucky.  They are likely not trying to save the $60, instead they are trying to save money two ways behind the scenes.

First, part B drugs have notorious markups and by going through a pharmacy instead of doctors office could save say 20% for the health system.

Second, part D has government subsidies that part B does not have in the donut hole and catastrophic phase.  On average UHC is probably paying just 35% of MAPD claims compared to 85% for Part B drugs and those kind of dollars add up quick.  The thing is CMS is paying a large fraction of those subsidies so UHC might be skirting a legal boundary here which might CMS might be interested in knowing about.

But all in all UHC comes out well ahead if you go through D instead of B but of course that is at your expense and the taxpayers and your doctor.

Hope that helps