A story about a patient who received a bill from a hospital for about 30 million yen, but was able to negotiate it down to about 5.6 million yen using AI.

'I received an exorbitant bill of $195,000 (about 29.7 million yen) from the hospital, but by negotiating using Anthropic's chat AI, Claude and ChatGPT, I was able to reduce it to $37,000 (about 5.6 million yen),' a story was reported on the short message posting SNS Threads.

Threads user Matt Rosenberg (@nthmonkey) 's brother-in-law was rushed to the hospital after suffering a heart attack in June 2025 and died within four hours. However, the hospital bill he received later showed an exorbitant amount of $195,000. So Rosenberg decided to help his sister-in-law negotiate medical expenses.

Rosenberg first estimated how much he would have paid if he had enrolled in Medicare , the public health insurance system in the U.S., to get a baseline for negotiation. The initial bill he received had very vague categories, so he asked for a more detailed bill, but the category codes on the bill were hospital-specific and didn't match Medicare's database.

So Rosenberg asked for an invoice with standard Physician Procedural Terminology (CPT) codes, but got no response. When he contacted them again, he got the excuse, 'Oh, they meant to send it to me. I upgraded my computer five months ago and nothing worked.'

After finally obtaining the bill with the CPT codes, Rosenberg fed it into the chat AI, Claude. Claude then explained to him that Medicare's rule states that when a particular CPT code is applied, all other procedures and supplies during that procedure are ineligible for billing. However, the hospital had billed for the major CPT code, and then listed individual CPT codes for minor items that would not have been billed, resulting in duplicate billing.

The total amount of these duplicate bills, which Medicare would not pay, reached more than $100,000. The bill also included CPT codes that only apply to hospitalized patients, even though my brother-in-law was never admitted to the hospital because he died shortly after arriving.

Furthermore, according to Medicare, the ventilator service listed on the bill 'cannot be billed on the same day as intensive care.' Other consumables were also billed at exorbitant prices, ranging from 500% to 2,300% of Medicare's payment. 'In essence, hospitals set their own rules and prices, and thought they could squeeze money out of ignorant people,' Rosenberg said.

When Rosenberg told the hospital that the bill was exorbitant, they asked her to apply for 'charitable assistance' instead of lowering the bill. However, her sister-in-law, who was responsible for paying the bill, was wealthy enough to receive a $1 million life insurance payout upon her husband's death, making the bill ineligible for charity. The hospital's request for charitable assistance instead of lowering the bill is apparently due to the hospital's obligation to provide charitable services in order to qualify for tax-exempt status.

Rosenberg criticized the hospital's demands as a messy system that makes it seem like they're doing people a favor instead of canceling unnecessary claims. So, with Claude's help, Rosenberg wrote a letter to the hospital pointing out their billing violations and threatening legal action, publicity, and a subpoena to Congress if they didn't accept Medicare-level payments.

By clearly stating in the letter that they were negotiating the amount and that they were not asking for charity, Rosenberg put the hospital in a position where they could not argue in court or publicly. In fact, Rosenberg says that they were prepared to take these measures if the hospital did not meet their demands. In the end, the hospital relented and agreed to the $37,000 demand.

Rosenberg made full use of the AI assistant during the negotiations, but didn't rely on it. He personally researched important findings to ensure their accuracy. He also signed up for a one-month ChatGPT subscription in addition to his existing $20-a-month Claude subscription, which he says has paid off.

'Hospitals know they're criminals, so if you confront them properly, they'll back down. It's not a yelling match, it's a lawyer-written letter, with the right intonation, tone, and threats,' Rosenberg said. 'Ultimately, the biggest lesson I learned is that you should never pay more than Medicare, the largest health care payer in the country, will cover. I have access to the tools to figure that out, but the moral issue is clear. No one should have to pay more out of pocket than Medicare will cover. No one. We can't let hospitals get away with this anymore.'

This experience has become a hot topic on the social news site Hacker News, with many similar stories being shared.

Using AI to negotiate a $195k hospital bill down to $33k | Hacker News
https://news.ycombinator.com/item?id=45734582

One user commented , 'I received advice from ChatGPT and was able to negotiate with the insurance company after they refused to pay my 6-year-old child's life-threatening surgery just before it was due for treatment.' Another user said, 'I was billed $4,000 (approximately 600,000 yen) for the ambulance costs to transport my daughter to the hospital, but by using a medical bill negotiation service that I happened to be subscribed to through my employer's benefits, I was able to reduce the bill to $500 (approximately 75,000 yen).'

There were also many voices criticizing the medical billing structure in the United States itself, with some users pointing out that 'hospitals and insurance companies are asking for the maximum amount they can, knowing that many people will pay what they are told out of fear of them,' and 'both insurance companies and hospitals are dirty money-making machines.'