Funding profile · Health data infrastructure

Ribbon Health

Four Form D notices, $15.5 million on the SEC record, a $43.5 million Series B that produced no filing, and a December 2024 exit to H1 at an undisclosed price.

$15.5MTotal sold across four Form D filings, 2017 to 2021
$43.5MSeries B announced Nov 2021, no Form D on file
$55MTotal raised, company-reported (Nov 2021)
$283.5MSeries B valuation, PitchBook via TechCrunch

Data as of September 23, 2026. Company-reported figures are labeled. All SEC amounts are as of the filing date.

Rounds at a glance

When Round Amount Investors Source
Sep 2017 Seed, as HealthWiz, Inc. $110,000 sold of $1,500,000 offered 3, unnamed Form D
Feb 2018 Seed extension, as HealthWiz, Inc. $90,000 sold of $1,050,000 offered 3, unnamed Form D
Feb 2020 Series A $10.25M announced; $11,819,986 sold per filing Led by Andreessen Horowitz; Y Combinator, BoxGroup, Nat Turner, Vivek Garipalli Form D + release
Feb 2021 Unannounced offering $3,500,000 offered and sold 2, unnamed Form D
Nov 2021 Series B $43.5M announced Led by General Catalyst; Andreessen Horowitz, BoxGroup, Rock Health, Sachin Jain Company release
Dec 2024 Acquisition by H1 Cash and stock, amount not disclosed H1 Acquirer-stated

What the filings show

Ribbon Health, Inc. · Form D · filed Feb 26, 2021

First sale
Feb 19, 2021
Offered
$3,500,000 equity and rights to acquire equity
Sold
$3,500,000 · $0 remaining
Investors
2 · average $1,750,000
Exemption
Rule 506(b)
Related persons
Anton Maslak (executive officer, director); Nathaniel Fox (executive officer, director); Julie Yoo (director)
Filing
SEC EDGAR, CIK 0001716554

Ribbon Health, Inc. · Form D · filed Feb 26, 2020

First sale
Feb 11, 2020
Offered
$11,819,986 equity
Sold
$11,819,986 · $0 remaining
Investors
32 · average about $369,000
Exemption
Rule 506(b)
Related persons
Anton Maslak; Nathaniel Fox; Julie Yoo (director), added since the 2018 filing
Filing
SEC EDGAR, CIK 0001716554

HealthWiz, Inc. · Form D · filed Sep 8, 2017 and Feb 20, 2018

First sales
Aug 25, 2017 · Feb 7, 2018
Offered
$1,500,000 then $1,050,000
Sold
$110,000 then $90,000
Investors
3 each · minimum accepted $25,000 in 2018
Exemption
Rule 506(b)
Related persons
Anton Maslak; Nathaniel Fox. 125 Western Avenue, Boston. Delaware, incorporated 2016
Filing
SEC EDGAR, CIK 0001716554

Reading the filings

  1. The SEC record captures less than a third of the reported capital.The four filings add to $15,519,986. The company reported $55 million in November 2021, and trackers report $53.8 million. The difference is roughly $38 million, most of it the Series B. Issuers that raise under Section 4(a)(2) rather than Regulation D file no Form D, so the gap is not evidence that no money moved.
  2. The Series A filing is larger than the Series A press release.The February 26, 2020 release announced $10.25 million. The Form D filed the same day reports $11,819,986 sold to 32 investors, a difference of $1,569,986. A filing that folds in converting notes from the HealthWiz period would explain it. Neither number has been amended.
  3. The filing landed on the deadline, the same day as the news.First sale February 11, 2020; Form D filed February 26, 2020, 15 days later and the last day allowed. The press release went out that same day. The 2021 filing moved faster: first sale February 19, filed seven days later.
  4. February 2021 looks like a bridge, not a round.$3,500,000 offered and fully sold to exactly two investors, $1,750,000 each on average, with no press release. Nine months later came the $43.5 million Series B led by General Catalyst. Two large checks with no announcement, followed by a priced round, is the shape of insiders extending runway into a raise.
  5. The board on paper never caught up with the board in the press.Julie Yoo of Andreessen Horowitz appears as a director on the 2020 and 2021 filings. Holly Maloney of General Catalyst was announced as joining the board with the Series B, but because no Form D followed that round she appears in no SEC filing here. The last Form D under this CIK is dated February 26, 2021.
  6. The founder files under a different first name.Every filing lists Anton Maslak as an executive officer and director; the chief executive is publicly Nate Maslak. Nathaniel Fox appears on all four, and the pair are the only related persons on the HealthWiz filings.

Commercial signals

Signal Detail Source type
Exit Agreement signed Dec 12, 2024, closed in late December, announced Jan 8, 2025. Cash and stock, amount undisclosed. Now sold as H1 for Health Plans and Digital Health. Acquirer-stated
Revenue and scale More than 50 customers and revenue in the tens of millions, with 20 million to 25 million Americans a year using it to find a provider, per Ariel Katz. Unaudited. Acquirer-stated
Valuation $283.5 million at the 2021 Series B, per PitchBook data cited by TechCrunch. No filing confirms it. Independent
Demand driver CMS found 52.20% and 48.74% of Medicare Advantage directory locations inaccurate in consecutive audit rounds. The REAL Health Providers Act, in the Consolidated Appropriations Act, 2026, makes accuracy a scored and published metric from plan year 2028. Public record
Public funding No NIH or NSF awards and no federal prime contracts found. Entirely privately financed on the record. Not found

What to watch

  • No new Form D has been filed under CIK 0001716554 since February 26, 2021. A further filing would signal the entity is still raising rather than folded into H1.
  • Whether H1, which has raised about $193 million and says it is profitable, ever discloses a price for the transaction.
  • Whether the Ribbon API keeps its own brand and endpoints, the cleanest read on whether H1 bought a product or a dataset.
  • Comparable exits among provider data vendors as REAL Act deadlines approach in 2028 and 2029.

The Ribbon Health story on Healthcare DiscoveryHealthcare Discovery

Related companies

  • Memora Health: Shared investor: Andreessen Horowitz. A text messaging platform that automated patient follow up for Mayo Clinic, Penn Medicine and more than fifty other provider organizations
  • Eligible: Shared investor: Andreessen Horowitz. A REST API that turns the HIPAA transaction formats behind insurance eligibility, claims and remittance into JSON
  • 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
  • Medmonk: Shared investor: Andreessen Horowitz. It began as a pharmacist’s spreadsheet for finding money for patients who could not pay for their drugs

Sources

  1. Public recordForm D, HealthWiz, Inc., CIK 0001716554SEC · Sep 8, 2017
  2. Public recordForm D, HealthWiz, Inc.SEC · Feb 20, 2018
  3. Public recordForm D, Ribbon Health, Inc.SEC · Feb 26, 2020
  4. Public recordForm D, Ribbon Health, Inc.SEC · Feb 26, 2021
  5. Public recordOnline Provider Directory Review Reports, Rounds 2 and 3CMS · 2018
  6. IndependentHealthcare analytics platform H1 has acquired Ribbon, backed by a16z and General CatalystTechCrunch, Marina Temkin · Jan 8, 2025
  7. IndependentH1 acquires Ribbon Health to expand its reach to health plan, digital health marketsFierce Healthcare, Heather Landi · Jan 8, 2025
  8. IndependentWhy General Catalyst, a16z, and Rock Health are backing Ribbon Health’s $43.5 million funding roundForbes, Seth Joseph · Nov 16, 2021
  9. CompanyRibbon Health raises $10.25 million; launches cost and quality solutionGlobeNewswire · Feb 26, 2020
  10. CompanyRibbon Health raises $43.5M Series B to become the leading API data platform in healthcarePR Newswire · Nov 16, 2021
  11. CompanyH1 welcomes former FDA commissioner to board, acquires Ribbon Health, unveils 2025 roadmapGlobeNewswire · Jan 8, 2025

Compiled from SEC and other public records and published reports as of September 23, 2026. Form D notices report offerings under Regulation D; amounts reflect the filing date and may not capture later sales. Healthcare Venture Capital Fund holds no position in Ribbon Health or H1. This page is not an offer to sell or a recommendation to buy any security.