ER visit cost-sharing in Oxnard-Thousand Oaks-Ventura, CA: what patients actually pay

From 511 real out-of-network emergency items in federal surprise-billing dispute files (2025), here is what patients in Oxnard-Thousand Oaks-Ventura, CA were charged in cost-sharing, by ER visit code:

Visit code	Cases	25th pct	Median	75th pct	90th pct
99283	66	$28	$32	$43	$143
99284	258	$38	$54	$68	$95
99285	187	$50	$85	$127	$149

Nationally, patient cost-share for the same ER code in the same city varies up to 52x. Part of that is the qualifying payment amount — the benchmark your share is computed from, which a federal appeals court ruled in August 2026 was being calculated unlawfully — and part is where you sat in your deductible and coinsurance. If your number is high for your code here, ask your plan in writing how it was calculated, including the qualifying payment amount: you are entitled to that answer either way, and it is the first step of any dispute.

Your rights on an emergency bill

Under the No Surprises Act you owe only in-network cost-sharing for emergency care, even at an out-of-network ER.
Balance bills for protected emergency services are generally prohibited.
Ask in writing for the itemized bill and how your cost-share was calculated, including the qualifying payment amount.

Now turn the number into a dispute. Knowing your percentile is step one; the letter that cites it, the visit-code check, and the deadlines are the rest. Medigami builds those from your actual bill — medigami.com