Funding profile · Healthcare revenue cycle AI

LunaBill

No SEC Form D has been filed under LunaBill’s name. What exists is a Y Combinator batch placement, a Founders, Inc. listing, a small seed figure from an aggregator, and an investor list confirmed in only one place.

$0SEC Form D on file for LunaBill as of Sep 25, 2026
$100KSeed round reported by a funding aggregator, Mar 2026
$500KTotal raised, per PitchBook; may restate Y Combinator’s standard batch check
5Of 10 investors named by PitchBook; 1 independently confirmed

Data as of September 25, 2026. Company-reported and aggregator figures are labeled.

Rounds at a glance

When Round Amount Investors Source
Fall 2025 Y Combinator, F25 batch Not disclosed; YC’s standard terms are $500,000 for 7% Y Combinator Accelerator record
Reported Jan 1, 2025 Accelerator or incubator deal, per PitchBook Not disclosed Not disclosed Aggregator
Reported Nov 26, 2025 Early Stage VC, per PitchBook Not disclosed Founders Future, Founders, Inc, Garage Capital, Lobster Capital, Pioneer Fund (5 of 10 listed investors) Aggregator
Published Mar 24, 2026 Seed round, per a funding news aggregator $100,000 Not named Aggregator, contains an error

What the filings show

A search of SEC EDGAR for “LunaBill” and for Form D filings under that name returned no matches as of September 25, 2026. This review’s records file, built separately from EDGAR’s full text search, also lists none.

Reading the numbers that exist

  1. The $100,000 figure comes with a factual error attached.The aggregator Signalbase describes LunaBill, in the same article that reports the $100,000 round, as a “Y Combinator Winter 2025 cohort participant.” LunaBill’s own Y Combinator page and a Y Combinator branded LinkedIn post both call it Fall 2025, F25. Y Combinator runs no Winter 2025 batch by that name, so the dollar figure should be held loosely.
  2. PitchBook’s $500,000 total funding figure matches Y Combinator’s standard check size.YC invests $500,000 for 7% equity in every batch company, per an independent healthtech blog covering F25. PitchBook’s figure may simply restate that, not add a separate round.
  3. Only one of five listed investors is independently confirmed.PitchBook names Founders Future, Founders, Inc, Garage Capital, Lobster Capital and Pioneer Fund, with no amounts or dates. Founders, Inc. confirms itself on its own portfolio page; the other four appear nowhere else.
  4. The founding year disagreement matters here too.PitchBook and Founders, Inc. date LunaBill to 2024, a year before its Fall 2025 YC batch; YC’s own page lists 2025. If 2024 is right, a year of pre-YC capital may sit uncounted above.
  5. PitchBook’s own deal table has three rows and almost no data.Two “Accelerator/Incubator” entries and one “Early Stage VC” entry dated November 26, 2025, all with amount and valuation left blank. Consistent with small, undisclosed tranches, not one priced round.

Commercial signals

Signal Detail Source type
Named customer Nutex Health, a 24 campus system. Company says $32M+ of AR worked in 30 days, zero added headcount, days in AR down from 45 to 7, cost per claim down from $22.28 to $2.00. Company-stated
Contracted revenue $764,000 contracted ARR in LunaBill’s earlier YC profile text, $428,000 already live, remainder due live by Jan 2026. Company-stated
Call volume 50,000+ calls in the earlier profile text, rising to 60,000+ calls and 90,000+ monthly payer interactions portfolio-wide later. Company-stated
Named partners UC health systems, Mayo Clinic and Experian Health named in the earlier profile text; later text and the current site name none, only unnamed systems and RCM firms. Not confirmed independently
Certifications HIPAA compliant and SOC 2 Type II certified, per the company, with a public trust center at trust.lunabill.com. Company-stated

What to watch

  • A first Form D, if a future round is raised under Regulation D and crosses a reporting threshold.
  • Whether PitchBook attaches an amount and date to the “Early Stage VC” round it lists for November 2025.
  • Confirmation, beyond Founders, Inc’s own portfolio page, of the other four PitchBook-listed investors.
  • Whether LunaBill discloses contract terms beyond the “share of net collections” pricing on its site.

The LunaBill story on Healthcare DiscoveryHealthcare Discovery

Related companies

  • Avro Life Science: Shared investor: Garage Capital. Two University of Waterloo first years set out to put a generic allergy pill into a sticker
  • Lilia: Shared investor: Garage Capital. A Y Combinator backed service that bundled discounted egg freezing cycles with a single point of contact for scheduling, meds, and clinic referrals
  • Candid Health: Also in Healthcare IT. Billing software built to get a medical claim right before it ever leaves the clinic, now sold to more than 200 provider organizations
  • Cair Health: Also in Healthcare IT. A San Francisco startup building a roster of named AI agents, Clark, Ella, Chloe, Dennis, Paige and Eve, to run medical billing end to end

Sources

  1. Accelerator recordLunaBill company profile and Launch YC postY Combinator · accessed Sep 25, 2026
  2. Accelerator recordLunaBill portfolio listingFounders, Inc. · accessed Sep 22, 2026
  3. AggregatorLunabill company profile, funding and investor tablePitchBook · accessed Jul 27, 2026
  4. AggregatorLunaBill Secures $100K Seed RoundSignalbase · Mar 24, 2026
  5. AggregatorLunaBill company pageSeedtable · accessed Jul 13, 2026
  6. AggregatorHow LunaBill is Transforming Healthcare Billing with AIReforgers · Jan 2026
  7. Independent10 healthtech startups in Y Combinator’s Fall 2025 batch (YC F25)All Health Tech · Nov 21, 2025
  8. IndependentLunaBill: AI call center for healthcare billing teamsLinkedIn, Y Combinator account, Mike Liu · Nov 11, 2025
  9. Public recordSEC EDGAR company and Form D search for “LunaBill”SEC · accessed Sep 25, 2026, no matches
  10. CompanyLunaBill homepage and FAQlunabill.com · accessed Sep 25, 2026

Compiled from SEC EDGAR, Y Combinator and Founders, Inc. public listings, funding aggregator data and published company statements as of September 25, 2026. No SEC Form D was found for LunaBill; aggregator figures for funding and investors are unaudited and, in at least one case, published alongside a factual error about the company’s Y Combinator batch. Healthcare Venture Capital Fund holds no position in LunaBill. This page is not an offer to sell or a recommendation to buy any security.