Since January 1, 2021, every hospital in the United States has been required by federal rule to publish its prices. Not a brochure, not "call for an estimate": a machine-readable file with the actual dollar amounts it charges and has agreed with insurers. The rule is 45 CFR 180, issued by the Centers for Medicare & Medicaid Services (CMS), and it is the reason a site like this one can exist.
What the rule requires
Every hospital licensed in the US must publish two things:
- A machine-readable file with its standard charges for every item and service it provides. "Standard charges" means five different numbers: the gross charge (the chargemaster list price), the discounted cash price for people paying themselves, the payer-specific negotiated charge for each insurance plan the hospital has a contract with, and the de-identified minimum and maximum negotiated charges.
- A consumer-friendly display of at least 300 "shoppable services", either as a price list or through an online estimator tool. Seventy of those services are named by CMS (colonoscopy, MRI of the brain, a knee replacement, a normal delivery, common lab tests); the hospital picks the rest.
From 2024 the file has to follow a CMS template, either CSV or JSON, so it can be read by software. From 2026 the template (version 3.0) also requires hospitals to state what insurers actually paid, not just the contracted rate, and to include their National Provider Identifier so the file can be linked to the hospital unambiguously. Every hospital must also place a small text file, cms-hpt.txt, at the root of its website that points to where the machine-readable file lives.
What is in the file
A typical file has tens of thousands to several million rows. Each row is one item or service, identified by a billing code, and one price. The codes are the ones on your bill:
- CPT and HCPCS codes for procedures, tests and outpatient services (a colonoscopy is 45378, a brain MRI with and without contrast is 70553).
- MS-DRG codes for inpatient stays (a hip or knee replacement without complications is DRG 470).
- Revenue codes, chargemaster numbers and drug codes for everything else.
For each code the file lists the gross charge, the cash price, and then one row or column per insurance plan with the negotiated amount. Large hospitals contract with dozens of plans, so a single procedure can have fifty or more prices in the file. The biggest files we read are over a gigabyte.
Why the files are hard to use
The rule was written so that the data would exist, not so that a patient could use it directly. Three things make the raw files hard:
- Size and format. A 700 MB CSV does not open in a spreadsheet. Files in the older versions of the template, or in hospitals' own layouts, need custom parsing.
- Same code, several lines. A hospital may list "HEAD CT" and "HEAD CT LIMITED" both under code 70450 with different prices, because they are different lines in its chargemaster. Nothing in the file says which one you would be billed.
- Missing pieces. Some hospitals leave out cash prices for many services, list negotiated charges as a percentage or a formula instead of a dollar amount, or omit the code entirely. Roughly one hospital in six publishes nothing readable at all, despite fines of up to $2 million a year for the largest hospitals.
How PricedCare reads them
We start from the official CMS list of hospitals (about 5,400 with Medicare certification), find each hospital's cms-hpt.txt, download the file it points to, and read it line by line. We keep only the rows for the shoppable services we track, skip rows with modifiers or drug units, and store each price with the hospital, the code, the payer if any, and the date the hospital put on its file. Where the same code appears on several lines, we show the lowest cash line and say how many lines there were.
We check the file's own hospital name and NPI against our list, because a health system's cms-hpt.txt often lists the files for all of its hospitals under one address, and a file that does not match any hospital we know is set aside rather than guessed. We re-read every file monthly. Every number on the site links back to the file it came from.
What the price does and does not tell you
A hospital's cash price for a procedure is the facility's own charge for that service. It does not include the physician who performs it, anesthesia, pathology or radiology reads, which are usually billed separately. It is not a quote: what you are eventually billed depends on what is done during the visit. What it is, is the number the hospital itself has published as its price, which is more than anyone could get in writing before 2021.
If you are paying yourself, the cash price is the starting point of a conversation. If you have insurance, the negotiated rate for your plan is what your deductible and coinsurance are calculated from, and it is sometimes higher than the cash price, which you are allowed to ask for instead.