LunaBill

Cover Block

Name	LunaBill
Tagline	AI voice agents automating insurance claim calls for healthcare billing
Headquarters	San Francisco, CA, USA
Founded	2025
Stage	Seed
Business Model	SaaS
Industry	Healthtech
Technology	AI / Machine Learning
Geography	North America
Growth Profile	Venture Scale
Founding Team	Co-Founders (2)
Funding Label	Seed (total disclosed ~$100,000)

Links

• Website: https://lunabill.com/
• LinkedIn: https://www.linkedin.com/company/lunabill/
• X / Twitter: https://x.com/lunabillhq

Executive Summary

LunaBill automates the tedious, time-consuming process of insurance follow-up calls for healthcare billing teams using AI voice agents [Y Combinator, 2025]. Founded in San Francisco in 2025, the company emerged from Y Combinator's F25 batch with a product deployed across initial health system clients, claiming to have processed over 60,000 calls and recovered more than $30 million in payments [Y Combinator, 2025]. Its core differentiation is a voice agent fine-tuned on a proprietary dataset of 1.2 million call transcripts [Y Combinator, 2025].

Co-founders David Day and Suhail Parry launched the venture, which has secured a $100,000 seed round from investors including Y Combinator and Founders, Inc. [Signalbase, 2025]. The business model is SaaS, targeting hospital and clinic billing departments.

Data Accuracy: YELLOW -- Key traction and product claims are sourced primarily from the company's Y Combinator profile; a single external source confirms the seed round amount.

Taxonomy Snapshot

Axis	Classification
Stage	Seed
Business Model	SaaS
Industry / Vertical	Healthtech
Technology Type	AI / Machine Learning
Geography	North America
Growth Profile	Venture Scale
Founding Team	Co-Founders (2)
Funding	Seed (total disclosed ~$100,000)

How the Company Got Here

LunaBill was founded in 2025 in San Francisco, California, as a participant in the Y Combinator F25 batch [Y Combinator, 2025]. The company operates as a SaaS provider, with its core business focused on deploying AI voice agents to automate the labor-intensive process of insurance claim follow-up calls for healthcare billing departments [Y Combinator, 2025]. The founding team includes David Day and Suhail Parry, with Yash Raj Singh Thakur also listed as a founder in some public records [Y Combinator, 2025] [LinkedIn, 2026].

The company reports having automated over 60,000 insurance calls, saving an estimated 20,000 hours for billing teams and facilitating the recovery of more than $30 million in payments for its clients [Y Combinator, 2025]. The company also cites partnerships with UC health systems, Mayo Clinic, and Experian Health [Reforgers, 2026].

Capitalization began with a seed round in November 2025, which raised $100,000 [Signalbase, 2025]. Investors in this early stage include Y Combinator, Founders, Inc., and Pioneer Fund [Crunchbase, 2025] [Founders, Inc., 2025].

Data Accuracy: YELLOW -- Founding details and funding round confirmed by Crunchbase and Y Combinator. Traction metrics and partnerships are sourced solely from company and affiliated launch pages.

Product and Technology

The product is a voice automation layer for the most labor-intensive part of healthcare revenue cycle management. LunaBill’s AI agents are designed to handle the repetitive, time-consuming phone calls billing staff make to insurance payers, a process the company claims consumes 80% of a biller’s workload on calls averaging 30 minutes each [Y Combinator, 2025]. The core functionality includes claim status checks, appeals follow-ups, reprocessing requests, and navigating payer interactive voice response (IVR) systems [Y Combinator, 2025].

Technical differentiation is framed around scale and proprietary training data. The platform supports up to 100 concurrent AI agents per client [Y Combinator, 2025]. The underlying voice models are fine-tuned on a proprietary dataset of 1.2 million healthcare call transcripts [Y Combinator, 2025]. Integration is described as working with “any billing software and EHR” [Y Combinator, 2025].

Data Accuracy: ORANGE -- Product claims and metrics are sourced primarily from the company's YC launch page and website, with limited independent verification.

Where the Demand Sits

The core appeal of LunaBill's proposition lies in the scale of administrative waste within the U.S. healthcare revenue cycle. The company's primary wedge is the manual process of insurance claim follow-up. According to the company's Y Combinator launch materials, 80% of a billing team's workload is spent on insurance calls that average 30 minutes each [Y Combinator, 2025]. The global healthcare RCM market was valued at $216.5 billion in 2023 and is projected to reach $405.9 billion by 2030 [Fortune Business Insights, 2024].

Metric	Value
Claim Follow-up Workload	80 %
Average Call Duration	30 minutes
Global Healthcare RCM Market (2023)	216.5 $B
Projected RCM Market (2030)	405.9 $B

Data Accuracy: YELLOW -- Market sizing for the broader RCM sector is from a third-party report. The core workload statistic (80%, 30 minutes) is sourced solely from the company's Y Combinator materials.

Competitive Landscape

LunaBill enters a market defined by manual labor, positioning its automation as a productivity layer atop existing billing software. The competitive map splits into three layers: legacy software vendors, adjacent process automation tools, and a nascent set of AI-native challengers. Incumbent revenue cycle management (RCM) platforms like Epic, Cerner, and Athenahealth provide the core billing systems but leave the telephonic follow-up work to human staff. Adjacent substitutes include robotic process automation (RPA) tools like UiPath and dedicated call center automation platforms like Talkdesk.

LunaBill claims an edge in its proprietary dataset of 1.2 million healthcare call transcripts [Y Combinator, 2025]. This edge is perishable, as it relies on continued data accumulation and could be eroded if a well-funded incumbent or a large RCM vendor decides to build or buy a similar solution.

Data Accuracy: YELLOW -- Competitive analysis is inferred from market structure; no direct competitors are named in sources. LunaBill's claimed differentiators are sourced from company and Y Combinator materials.

Opportunity

The prize for automating the manual, high-volume insurance follow-up calls is a multi-billion-dollar market for operational efficiency. Early metrics suggest the solution materially changes unit economics: billers reportedly handle 300+ follow-ups per day versus 25 per day pre-LunaBill [Y Combinator, 2025].

Scenario	What happens	Catalyst	Why it's plausible
Dominant RCM Partnership	LunaBill becomes the exclusive or preferred AI voice agent embedded within a major RCM software platform.	A formal technology or reseller partnership with a named enterprise software vendor or RCM firm.	The product claim of integration with "any billing software and EHR" [Y Combinator, 2025] and an early mention of partnerships with UC health systems and Experian Health [Reforgers, 2026] suggest a strategy focused on integration.
Vertical SaaS Expansion	The company expands from automating calls to managing the entire denial and appeal workflow.	The launch of a complementary software module for denial analytics, automated appeal letter generation, or payer performance benchmarking.	The existing product already handles appeals follow-ups and provides real-time analytics [Y Combinator, 2025] [Shyft, 2026].

Data Accuracy: YELLOW -- Opportunity framing relies on company-cited market dynamics and unverified traction metrics; growth scenarios are extrapolated from product claims and limited partnership mentions.

Sources

1. [Y Combinator, 2025] LunaBill: AI Voice callers for healthcare billing teams | https://www.ycombinator.com/companies/lunabill
2. [Signalbase, 2025] LunaBill Secures $100K Seed Round | https://www.trysignalbase.com/news/funding/lunabill-secures-100k-seed-round
3. [Crunchbase, 2025] LunaBill - Crunchbase Company Profile & Funding | https://www.crunchbase.com/organization/lunabill-7f08
4. [LinkedIn, 2026] David Day - Atlassian | LinkedIn | https://www.linkedin.com/in/davidedday/
5. [Reforgers, 2026] How LunaBill is Transforming Healthcare Billing with AI | https://reforgers.com/startups/lunabill
6. [lunabill.com, 2025] LunaBill | Automate Your AR Calls | https://lunabill.com/
7. [Shyft, 2026] LunaBill: AI Voice Billing for Healthcare - Shyft | https://shyft.ai/tools/lunabill
8. [Founders, Inc., 2025] LunaBill, Automate Your AR Calls. | https://f.inc/portfolio/lunabill/
9. [Fortune Business Insights, 2024] Healthcare Revenue Cycle Management Market Size, Share & Industry Analysis | https://www.fortunebusinessinsights.com/healthcare-revenue-cycle-management-rcm-market-106769