Health IT · Insurance billing infrastructure

Eligible

A REST API that turns the HIPAA transaction formats behind insurance eligibility, claims and remittance into JSON. Fourteen years on, the company has stopped announcing funding and started announcing audits, and the service is still answering.

The oncologist who could not get paid

In 2010 Katelyn Gleason was a stage actor who had run out of stage. She took a sales job at DrChrono, a Mountain View startup putting medical records on iPads, and spent her days on the phone with practices.

One call redirected the next fifteen years. “During this time I met with one of the country’s top oncologists, who informed me that he was waiting on millions of dollars in insurance payments because his practice had filled out paperwork incorrectly,” she wrote in 2017. “It seemed unconscionable to me that he could barely keep his business solvent because of a couple of typos.”

She left, moved into a one room apartment on Castro Street with $5,000 in the bank, and spent nine months mostly in the Mountain View public library, teaching herself software and the plumbing of health insurance. By her own account the savings became about $25,000 of credit card debt before anything worked.

What a 270 is, and why it is hard

Every time a clinic checks whether your coverage is active, a file crosses the wire in a format called X12 EDI. The question is a 270. The answer is a 271. Claims go out as 837s, payment advice comes back as 835s, and the machine receipts in between are TA1, 997 and 999 files. These formats are mandated under HIPAA, they are decades old, and for most of their life the only way through them was a clearinghouse with a six month integration.

Gleason learned the spec herself. “It’s a 5010 spec and it’s a data spec. It’s an electric data interchange. It’s called X12 EDI.” The product idea was to wrap all of it in JSON and charge by the call, the way Stripe wrapped the card networks. The company still describes itself as the first to release “the customer-facing concept of a REST API for these essential services, in 2012.”

By 2015 the price was five cents per transaction for the first 250,000 calls, and the named customers were Kareo, Remedy Partners, RadNet, Simplee and EveryMove.

Twice through Y Combinator, once as the founder

Gleason had already been through Y Combinator once, as DrChrono’s first employee. Getting back in as a founder took a working demo and a lucky interview. A partner had just been hit by an unexpected medical bill; she asked about his plan and the test, turned the phone around, and explained his deductible. Eligible joined the Summer 2012 batch and Rock Health the following year.

The co-founder story is less tidy. She recruited two technical co-founders early, a teenager and a full time bank engineer with four children, and lost both inside a year. Investors pushed her to replace them at once. She did not. She hired and trained the engineering team herself, and two early hires were given the co-founder title a year in. Neither is named on the company’s public pages today.

What kept the company going, in her telling, was one office hour with Paul Graham during a month when the team wanted to pivot. “You’ve built something, people want it, they are willing to pay for it, and the market is really big. Why give up now?”

Profitable, then quiet

The arc peaks around 2016 and 2017. Gleason told Indie Hackers that the company grew 8.4 times, reached profitability, held it a year, and only then raised again. Coverage from that period puts total funding above $25 million from Drew Houston, Naval Ravikant and Steve Huffman among others, and volume at about 14 million API calls a month. A Brooklyn office with nap nooks and a marble reception was photographed in February 2017.

Then the press stops. No funding announcement after 2017, no acquisition, no shutdown notice. In March 2023 the company posted Why We Limit Access to Our Platform, which opens by saying over 110,000 providers run eligibility or billing through Eligible each month, worth roughly $4.8 billion a year. Almost everything published since is an audit result.

What is proven, and what is still claimed

Read plainly: the company operates. The API answers, the status page is maintained by people who write post incident updates, and two demanding security assessments were completed in 2026 by a named third party. What went missing is not the business but the publicity. Market position, volume and customers rest on company statements, most eight years old, and the gap between a claimed $25 million and $2.68 million of filed offerings has never been reconciled.

What to watch

• Any Form D after January 2015. Eleven years without one, for a company that says it raised $25 million, is the loudest silence here.
• Renewal of the HITRUST r2 and NIST certifications, which expire in May 2028.
• A customer named after 2018, or a volume figure newer than March 2023.
• Whether the limited access policy survives rivals now raising large rounds to sell the same transactions.
• Whether the Y Combinator directory entry is ever corrected.

In their words

Related companies

• Apero Health: Shared investor: Andreessen Horowitz. An API driven practice management platform that folds scheduling, visit notes, insurance billing, patient payments and e-prescriptions into one system for medical
• Ribbon Health: Shared investor: Andreessen Horowitz. An API built to answer a question the American health system keeps getting wrong: is this doctor real, in network, and reachable at the number listed
• Fortuna Health: Shared investor: Andreessen Horowitz. A consumer app for getting onto Medicaid and staying on it, paid for by the hospitals and health plans that lose money when coverage lapses
• Camber: Also in Healthcare IT. An AI-driven platform that automates insurance billing for pediatric behavioral health and specialty care clinics, built on a claims database the company says now

Sources

1. Public recordForm D, Eligible Inc., 0001560548-12-000001SEC EDGAR · Oct 19, 2012
2. Public recordForm D, Eligible Inc., 0001560548-15-000004SEC EDGAR · Jan 29, 2015
3. Public recordEDGAR filing index, CIK 0001560548SEC · Sep 23, 2026
4. Public recordEligible Inc Status, components and incident feedStatuspage · Sep 23, 2026
5. Public recordHTTP responses from gds.eligibleapi.comDirect request · 2026
6. IndependentEligible Successfully Completes SOC 2 Audit with Zero ExceptionsPR Newswire · Sep 8, 2026
7. IndependentEligible’s Platform Services Attain HITRUST r2 and NIST CSF v1.1PR Newswire · Jul 7, 2026
8. IndependentEHNAC accreditationPR Newswire · 2018
9. IndependentGleason’s plan to upend medical billingTechCrunch · 2017
10. IndependentEligible raises $2.3 millionMobiHealthNews · 2015
11. IndependentMeet Katelyn GleasonBuilt In NYC · 2018
12. IndependentThe founder who went through YC twiceBuilt In NYC · 2017
13. InterviewEpisode 050Indie Hackers · 2018
14. Independent73. Katelyn GleasonFast Company · 2013
15. IndependentAPI catalog listingAPIs.io · 2026
16. CompanyMy Journey From Struggling Actress to Tech CEOWomen 2.0 · 2017
17. CompanyFemale Founder StoriesY Combinator · 2015
18. CompanyWhy We Limit Access to Our PlatformEligible blog · 2023
19. CompanyDirectory entry and LinkedIn pageYC and LinkedIn · 2026