Coinsurance

Coinsurance is your share of the cost of a covered service, calculated as a percentage of the allowed amount, and you generally pay it after you have met your deductible. HealthCare.gov’s example: with 20% coinsurance and an allowed amount of $100 for an office visit, you pay $20 once the deductible is satisfied.

The difference between coinsurance and a copayment is the difference between a percentage and a fixed dollar amount, and for a high-cost drug that difference is enormous. A $50 copay is $50 whatever the drug costs. Twenty percent coinsurance on a medication with a four-figure monthly price is a four-figure problem for you.

This is exactly why specialty formulary tiers matter so much for GLP-1 drugs. Lower tiers usually carry copays; specialty tiers frequently carry coinsurance. Two people can both have “covered” written on their approval letter and pay wildly different amounts, purely because one lands on a copay tier and the other on a coinsurance tier.

The one piece of good news is the out-of-pocket maximum. HealthCare.gov defines it as the most you have to pay for covered services in a plan year; after you reach it, the plan pays 100% of covered benefits. On a high-coinsurance specialty drug, that ceiling can be reached within a few months — brutal at the start of the year, much easier by summer. Budgeting for the year rather than the month is the only way to see that shape.

Worth asking: whether your drug carries a copay or coinsurance, what percentage, what the allowed amount is (not the list price), and what your out-of-pocket maximum is. Our savings calculator and cost-per-pound calculator put those numbers side by side, and the coverage overview explains how plan types differ.