Your hospital bill is probably wrong. Find out before you pay it.

If you've ever stared at a hospital bill and seen a string of numbers like 99284 or 71046 next to a dollar amount, you've met a CPT or HCPCS code. These codes exist so every provider in the country bills insurance the same way for the same service — but almost nobody translates them back into plain English for the patient actually holding the bill.

CPT (Current Procedural Terminology) codes describe the service performed — an ER visit, an X-ray, a blood draw. HCPCS codes cover supplies, drugs, and services CPT doesn't fully capture, like an "unclassified drug injection" (J3490). The first digit of a code range often tells you the category: 992xx is an office or ER evaluation, 7xxxx is imaging, 8xxxx is lab work.

The number after the code — the "level of complexity" — matters more than most patients realize. An ER visit billed as 99285 (high complexity) instead of 99284 (moderate complexity) can be a few hundred dollars more, and it's one of the most common places upcoding shows up: the code describes a more complex visit than what a service note or diagnosis actually supports.

Practically, when you're reading your bill: for every code, ask two questions. First, "does this description match what I remember happening?" Second, "does the billed amount look anywhere close to typical for this kind of service?" A routine blood draw (36415) billed at $38 is normal; the same code billed at $300 twice on one visit is a flag worth raising. This is exactly the two-step check BillAutopsy automates — translating every code to plain English and comparing the billed amount against typical rates — but you can do a rough version yourself with any code lookup and a little skepticism.

The federal No Surprises Act (NSA) protects patients from "balance billing" in specific situations: emergency care at any facility, and non-emergency care from an out-of-network provider at an in-network facility (think: the anesthesiologist you never chose, at a hospital that is in-network). In those cases, you generally can't be billed more than your plan's in-network cost-sharing amount — the provider and insurer are supposed to work out the rest between themselves.

What it does not do is regulate whether a specific charge or code was accurate, or protect you if you knowingly went out-of-network for a planned, non-emergency service and signed a consent form waiving NSA protections (this happens more than people realize — always read what you're signing at check-in). It's a billing-relationship law, not a coding-accuracy law.

Where it becomes useful in a dispute letter is when a bill shows a patient-responsibility amount that looks far larger than your plan's allowed cost-sharing — especially after an ER visit or a hospital-based specialist you didn't choose. Citing the NSA by name, along with CMS's guidance on qualifying payment amounts, signals to a billing office that you know this isn't the first dispute letter they've seen this month, and that you're asking for a specific correction, not just "please explain this bill."

This is exactly why BillAutopsy's dispute letter generator references the No Surprises Act and CMS guidance directly wherever a flagged charge looks like a balance-billing issue — it gives your letter the same structure a paid billing advocate would use, without the $300–$600 fee or the two-week wait.

1. The same code appears twice at the same price. Duplicate charges are the single most common error — a blood draw, a medication dose, or a supply fee billed once during intake and once again during processing. If two lines share a code and an amount, ask for an itemized explanation of why.

2. A code doesn't match your memory of the visit. If your ER visit was a quick check and a prescription, but the bill lists a "high complexity" evaluation code, that's a possible upcoding mismatch — the code describes more clinical work than what likely happened.

3. The price is far outside the typical range for that code. Every CPT code has a rough market range by region. A chest X-ray at $180 is normal; the same code at $650 is worth questioning, especially with no unusual circumstances noted.

4. A charge on the bill has no matching line on your EOB. If your insurer's Explanation of Benefits doesn't mention a charge that appears on your bill, either it wasn't submitted to insurance correctly or it shouldn't be there — either way, it's the provider's job to explain, not yours to just pay.

5. Your "amount owed" is much higher than your plan's allowed cost-sharing. This is the pattern the No Surprises Act was built to catch, especially for emergency or hospital-based care you didn't choose the provider for.

Proving any of these doesn't require a billing degree — it requires lining the bill up against the EOB, translating the codes, and writing down the dollar amount each flag is worth. That line-by-line comparison is the entire first half of what BillAutopsy automates the moment you upload your documents.