I had nice chat with a senior tech who told me that it has been a long standing policy by Medicare to disallow discount/coupons for anyone who has Plan D. Her explanation was not nearly as complete as yours but she did say Costco had just began enforcing it in their system.
I believe the tech you spoke with was even a little confused on the matter. I can assure you that at any time you can request that your prescription can be filled off of insurance (any commercial or medicare part D program) and a discount like GoodRx or Lowest Price Med can be used in its place, it is just highly discouraged and must be documented by the pharmacy that it is being requested. This is due to the mess of DIR fees that I had mentioned.
What has always been the case is if you have medicare part d (and other government plans, including Tri-Care, federal blue cross, etc.) you cannot use a coupon in conjunction with or instead of your insurance. These are those co-pay cards that you might see offered on TV while the drug is being advertised
"pay no more than $30* per month for the first 12 months of your prescription for Eliquis". What the dr office or person watching the commercial doesn't know is that little asterisk notes is that the coupon/copay card doesn't work with federal plans and/or has a maximum payout of $100 towards the $400 medication.
What Costco has is called the CMPP (Costco Member Prescription Plan) which came out during the hub bub of the $4 WalMart list, the Walgreens Prescription Savings Club, etc. about 10 years ago. It is a plan that is free if you are a Costco member and didn't have insurance. It would save you on average of $3-5 off cash scripts per 30 day supply.
10 years ago there wasn't an issue of DIR fees, but there was a huge thing with medicare part D called the doughnut hole or coverage gap where you would have to pay 100% out of pocket when you hit $xx,xxx amount of benefit and it would take $x,xxx to get to the other side of said doughnut hole, where coverage would pick up again. At that time people would rather buy their cheapest medications with cash on the CMPP which would help them not hit the doughnut hole as fast or at all and the restriction that Costco had of not being able to use CMPP if you had insurance had been adjusted to if the insurance wasn't paying for the prescription you could use CMPP.
That has since been tightened up and CMPP cannot be used anymore with anyone who has medicare part D period, which is what I believe the tech you spoke with was referring too.
Fast forward to today and the doughnut hole is not 100% out of pocket but has been shrinking to a max of 25% by 2020
https://q1medicare.com/q1group/MedicareAdvantagePartDQA/FAQ.php?faq=Will-the-Coverage-Gap-or-Donut-Hole-eventually-close-and-just-go-away-&faq_id=471&category_id=118
Ronnieboy--forgot to ask you what are "DIR fees"?
thx
Hard to explain but what DIR stands for is 'direct and indirect remuneration' a pull back on what a pharmacy benefits management company (PBM) has paid a pharmacy after it has already dispensed the medication. Here are a couple of boring articles:
https://www.specialtypharmacytimes.com/news/do-dir-fees-stand-a-chance-in-2018
http://www.drugtopics.com/blog/dir-fees-just-one-many-reimbursement-battles
But the basic idea is that a prescription is processed through your aetna medicare part D plan. Lets say it is for 30 days of metformin 500mg at one a day, a popular diabetes medication. The claim is processed online and as a pharmacy you are submitting which drug it is, the quantity of medication, how many days it is supposed to last the patient and a host of other stuff, one of which is the pharmacies usual and customary price for the prescription which is the term used if John Doe came in the pharmacy without insurance and said I want some metformin 500mg #30 cash please.
Lets say that your generic copay through Aetna is $5 for 30 days so no matter what you are only going to pay $5. Whatever your insurer is going to pay - lets say its $10 towards the claim - it is only going to cut a check to the pharmacy every 30 days for the past 30 days of claims so as a pharmacy you are waiting up to 60 days to get paid for a drug that left your pharmacy two months ago.
But lets go back and see what two retail pharmacies would submit for the claim of metformin 500mg #30 tabs. (these are hypothetical numbers)
WalMart submits all the info and says we want $35 for the script but our usual and customary charge for this is $4 because it is on our $4 list.
Walgreens says we want $120 for this because our usual and customary is $120 for the medication.
Aetna send back to Walmart: charge our member $4 because that is what your cash price is and we are sending you $0
Aetna send back to Walgreens: charge our member $5 because that is what his copay is and were going to send you $10 because that is all you are allowed to get for #30 metformin 500mg tablets. So walgreens gets $15 total and Walmart gets $4.
Now DIR fees come into the picture when Aetna says well you should be processing the patients prescription of metformin for 90 days instead of 30 because that increases compliance, negative mark. Based on the number of diabetic prescriptions for your whole chain we can see only a 60% compliance rate on refills so that is another negative mark. When all is said and done we are taking back (or basically withholding future payment of any other aetna insurance payments) $6 for the prescription. If you are walmart you just lost $2 for the script that you only received $4 for in the first place.
This is one reason why you see or read about these news stories when reporters are doing price comparisons and they show you the shocking price of some generic drug at Walgreens is $150 more than the lowest price from another pharmacy. Walgreens can max out the contract price of all drugs through the insurance because their usual and customary is out of this world high and typically always above a contracted price.