not necessarily. Family members on Plan C over 20 years

If I need to give an evaluation, I would give it an A-.  Why A-?  because sometimes there would be decoupling between the service providers claim filing (most the time with wrong codes) and the claim approval.

Over the 25 years there is NOT a single denial.  Hospitalization used to be $100 copay.  In last several years, it is a big fat ZERO. 

Drugs is 0 copay for generic.  $5 to $10 copay for drugs that cost $600, even to the insurance company because of brand name drugs. 

Plan C very much depends on WHERE you live, and WHO is the insurance company.  I can tell you FL seems to have the best plans offered.  CA plans are much inferior than what FL has.

A generalization on Plan C is always bad when you are really sick, is Too Misleading.  You need to research your OWN locale. 

Finally, a GOOD PCP is Very Important in any plan, but particularly in Plan C, as it is an HMO, all needed procedures are coordinated by your PCP with the specialists you need to see.  Usually PCP would tell you which specialists you need to see for your particular situation.  Either you do your own research to find a well-qualified, board certified specialist or ask your PCP for recommendation.  I do not see there is any difference to choose good doctors whether you are on HMO or PPO.  You make an appointment with specialist, who then sends a request to the PCP on why the patient needs to consult with specialist.  PCP then submits a request to Humana to ask for authorization for treatment.  Humana then approves the request so the PCP issues a Referral.

In 2021 and 2022 there were 2 hospitalization episodes - the bills of course looked horrendous, one was $90K+ for 3 days and the other one was $60K+, but Humana got a huge discount, basically paid about 15 to 20% on what the hospitals billed.  The patient's copayment is ZERO.

The patient sees a cadiologist and PCP every 6 months as maintenance for his AF condition which he was diagnosed 25 years ago.  There are other kinds of small issues though often just needs to make a call to PCP's office and he would order what needs to get done or prescribe some medication.

Again, your perception is not correct.  It TRULY depends.