Copay
Etymology
A twentieth-century American coinage from co- "together with" (Latin) + "payment" — the insured and insurer paying jointly. Short for "copayment", it spread with the growth of managed health care and remains largely specific to the US insurance system. Flag it as a modern industry coinage rather than an inherited word.
noun · /KOH-pay/
A fixed, usually small fee you pay for a covered medical service, with insurance paying the rest.
What it names
The predictable at-the-counter charge — useful for naming the flat fee you owe per visit, prescription, or test regardless of the total bill.
Example
Her plan charged a $25 copay for each specialist visit, no matter how long the appointment ran.
Related idea
Distinguish coinsurance, which is a percentage of the cost rather than a flat fee — a copay is $25 flat, while 20% coinsurance rises with the size of the bill.
See also