BioStack, a San Francisco healthcare data startup founded in 2025 by Sanat Mishra and Parth Patwa, has raised $9.5 million in a seed round led by Peak XV Partners, DCVC and Afore Capital, with participation from Emerson Collective, SV Angel, Verdict Capital, Streamlined Ventures and Y Combinator, according to Indian Startup News.

The valuation was not disclosed. The funding will go toward expansion across the US and international markets, development of its technology platform, and hiring for engineering and research teams.

The round stands out because it is not a bet on a new AI model but on the messy data layer beneath medical AI. Patient information in most health systems sits in separate silos: doctors' notes in one system, lab results in another, scans in a third, The Economic Times reports.

BioStack pulls these together into longitudinal records linking clinical notes, laboratory results, imaging, medications, treatment histories and outcomes, using de-identified data collected from each provider system to build proprietary datasets for medical research, drug development and AI training and evaluation.

Pushpak Kedia, VP at Peak XV, argued that the next frontier of healthcare AI depends not only on better models but on access to high-quality, longitudinal data reflecting how patients are treated over time, according to Indian Startup News.

Both Economic Times and Indian Startup News report that BioStack operates across India, the US, Brazil and Argentina, working with hospitals in all four countries and with access to more than 100 million de-identified patient records.

Indian Startup News adds that the startup claims to have combined several hundred thousand X-rays, MRI and CT scans, and several million telehealth audio transcripts with pathology and other clinical records.

The startup says this dataset can be used to train AI agents that help clinicians assess treatment options and likely patient outcomes, with use cases including disease modelling, biomarker discovery, patient stratification and analysis of how patients respond to treatment.

Its platform also includes workflows built around each healthcare provider's own data privacy protocols.

Indian Startup News reports that CEO Sanat Mishra conducted cancer genomics research at Stanford, Yale, Carnegie Mellon and the Max Planck Institute, and worked with AI labs as an early researcher on reinforcement learning tasks in healthcare and biotechnology, holding degrees from IISER Mohali and Carnegie Mellon.

CTO Parth Patwa is a former generative AI scientist at AWS and a former researcher at MIT, with more than 40 papers and over 1,800 citations at venues including CVPR, NeurIPS and EMNLP, and a master's degree from UCLA. The company went through Y Combinator's Spring 2026 batch.

Mishra framed the mission as building infrastructure that connects all clinical information, useful for clinicians making decisions today and for researchers and AI developers building the future of medicine.

The capital arrives as investor money into healthtech grows even as deal counts shrink: Indian Startup News, citing Tracxn data, reports that healthtech companies globally raised $22.8 billion across 1,150 rounds so far in 2026, versus $19.9 billion across 1,530 rounds in the same period of 2025 — roughly 15% more funding with about 25% fewer rounds.

In India, BioStack says it is helping connect cancer patients with an investigational cancer vaccine programme, where participating patients' clinical information supports biotech development work while eligible patients may access highly personalised investigational treatments.

It did not name the biotech company or vaccine involved.