Health tech & revenue cycle · Specialty clinic operations
Entropy
A two person team is building AI agents that read faxes, check insurance eligibility and chase prior authorizations for specialty clinics. The company started life in 2024 as a fintech compliance startup called Remo, pivoted to healthcare within its own Y Combinator batch, and has not named a clinic customer in public yet.
A referral by fax, in 2026
A specialty clinic in the United States still gets many of its new patients the same way it did twenty years ago: a fax, an email attachment, or a phone call from a referring doctor's office. Someone on staff has to read it, key the patient's details into the electronic health record, call the insurer to check coverage, and start the paperwork for a prior authorization. Entropy's pitch is that software can do that reading, keying and calling instead, and get faster at it the longer it runs.
On its Y Combinator launch page the company says it is “live across multiple clinic locations that process thousands of patient referrals monthly, now 90% faster than manual workflows.” No clinic is named, and no third party has verified the figure.
The problem, in the founders' telling
The company's account of the problem is specific about time and money. “Specialty clinics are drowning in manual tasks that are costing them billions of dollars and failing their patients and referrers,” the launch post says. It lists four failure points: intake staff manually processing faxes and forms, billing staff manually checking eligibility and submitting claims, patients waiting weeks for care, and clinics losing revenue to missed referrals and denied claims.
A company post on LinkedIn puts a number on the first of those: “The average practice spends 15+ hours a week just on hold with insurance companies.” That figure is company-stated and was not sourced to an outside study in the post.
Two founders, one healthcare story
Rabii Malik and Hashim Rehman are the company's co-founders. Entropy's own account says Malik worked at McKinsey building digital businesses, and Rehman handled pricing at Careem, the Middle Eastern ride hailing company, for millions of daily transactions. Neither claim has been checked against an outside source.
The origin story the founders tell is personal. “Living with chronic conditions for the past 10 years has been one of the hardest parts of my life,” Rehman wrote in a post on the company's LinkedIn page, describing having navigated healthcare systems in the United Kingdom, the United Arab Emirates and the United States. “Then my co-founder Rabii and I started talking to clinics in the US. Turns out the system is just as broken on their side,” he wrote. The Y Combinator launch post gives a parallel version: “Hashim spent a decade navigating referral hell while managing a chronic condition. Rabii watched his parents do the same.”
From Remo to Entropy
Before it was a healthcare company, it was a fintech one. Y Combinator's own listing for Entropy carries a “Previous Launches” entry describing a product that “We empower onboarding and compliance teams at financial institutions to get through cases faster and with higher accuracy.” Job listing aggregator profiles and cached recruiting pages tie that earlier product to the name Remo, in the same Y Combinator Summer 2024 batch, with Rehman listed as its co-founder and CTO. The company's current Y Combinator page lists its Y Combinator partner as Tom Blomfield and its founding year as 2024, spanning both identities.
By the time of the healthcare launch, in company materials accessed in 2026, the name had changed to Entropy and the product to specialty clinic intake and revenue cycle management. Whether the pivot happened smoothly or under pressure, and what it did to the company's cap table, is not disclosed anywhere found in this research.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| FDA and clinical trial records | No FDA 510(k), PMA or ClinicalTrials.gov record for Entropy, withentropy.ai, or Remo. As administrative and revenue cycle software, FDA clearance would not typically apply. | Not found |
| SEC Form D | None found under the names Entropy, Withentropy, or Remo tied to this company. Every Form D mentioning “Entropy” in an EDGAR full text search belongs to unrelated filers: investment funds, a crypto custodian, a media company, and an industrial capital fund. | Not found |
| Federal research grants | None found for this company. NIH and NSF awards under “Entropy” belong to Dynamic Entropy Technology LLC, an unrelated wound care biomaterials company with no apparent connection. | Not found |
| Peer reviewed literature | None found for the company or its product. PubMed results for “entropy” are unrelated papers on triboelectric nanogenerators, high entropy alloys and materials science. | Not found |
| Prior identity as Remo | Y Combinator's own page for Entropy lists a prior launch describing onboarding and compliance automation for financial institutions, the product associated with the name Remo in the same Summer 2024 batch. | YC data |
| Customers and scale | Company says it is “live across multiple clinic locations” processing “thousands of patient referrals monthly.” No clinic is named. | Company-stated |
| Compliance claims | Website states the product is “HIPAA and SOC 2 Type 2 compliant.” No auditor or report is named. | Company-stated |
| Funding and team status | An independent aggregator (Jobs with Startups) lists total raised as $500,000, a Y Combinator pre-seed dated September 2024, and states co-founder Hashim Rehman is shown as having left the company in April 2026. None of this is corroborated by a second source. | Independent, unverified |
Read plainly: almost everything known about Entropy comes from the company itself or from Y Combinator's own listings. There is no regulatory record, no federal grant, no litigated filing and no independent news article establishing the company's customers, revenue or current team. The one third party data point, a claim that a co-founder left the company in 2026, has not been checked against another source.
What to watch
- Whether the co-founder team is intact. An aggregator profile says Hashim Rehman left the company in April 2026; that claim has not been corroborated elsewhere.
- Named clinic customers, integration partners, or a disclosed contract value.
- A SOC 2 Type 2 report or named auditor to back the compliance claim on the website.
- Any SEC Form D, which would be the first public record of outside investment in the company.
- Independent press coverage. None was found as of this research.
In their words
“We're building an AI operating system for specialty healthcare that improves over time.”
Rabii Malik and Hashim Rehman, co-founders, Y Combinator launch post · Company-stated
“Healthcare is personal to us. Hashim spent a decade navigating referral hell while managing a chronic condition. Rabii watched his parents do the same.”
Y Combinator launch post · Company-stated
“Living with chronic conditions for the past 10 years has been one of the hardest parts of my life.”
Hashim Rehman, co-founder, company LinkedIn page · Company-stated
“Then my co-founder Rabii and I started talking to clinics in the US. Turns out the system is just as broken on their side.”
Hashim Rehman, co-founder, company LinkedIn page · Company-stated
“The average practice spends 15+ hours a week just on hold with insurance companies.”
Company LinkedIn page · Company-stated
“We're live across multiple clinic locations that process thousands of patient referrals monthly, now 90% faster than manual workflows.”
Y Combinator launch post · Company-stated
“Hashim Rehman, listed as CTO & Co-Founder, is shown as having left the company in April 2026; the company remains active and very small.”
Jobs with Startups, company aggregator profile, updated Jul 29, 2026 · Independent, unverified
Related companies
Sources
- CompanyEntropy company page
- CompanyLaunch YC: Entropy, The Operating System for Specialty Healthcare
- CompanyEntropy, Automated Patient Intake and RCM
- CompanyEntropy (YC S24) company page
- IndependentEntropy jobs and careers, company data profile
- Public recordNIH RePORTER, project 1R41DK123949-01, Dynamic Entropy Technology LLC (unrelated company)
- Public recordNSF award 2032325, Dynamic Entropy Technology LLC (unrelated company)
- Public recordSEC EDGAR full text search, Form D filings mentioning “Entropy,” all unrelated filers
- Public recordPubMed search results for “entropy,” all unrelated papers
- IndependentEntropy raises $25m in seed funding, a different, unrelated crypto custody company also named Entropy
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
