Assort Health, a startup that uses AI to automate patient communication for specialty healthcare practices, has raised about $50 million in a Series B round at a valuation of $750 million, according to three sources familiar with the deal. The latest round, which comes just four months after the company raised its $22 million Series A, was led by Lightspeed Venture Partners, these people said.

The company’s AI voice agents are designed to take over high-volume, repetitive tasks like scheduling, cancellations, and frequently asked questions normally managed by front desk staff, allowing human staff to focus on more complex or sensitive patient interactions.

Assort Health is one of several startups that recently raised new funding to use AI to alleviate patient phone call volume for medical offices.

Just last week, EliseAI, which automates customer services for real estate and healthcare office front desks, announced that it secured a $250 million Series E led by Andreessen Horowitz, valuing the company at $2.2 billion. Hello Patient, another AI-powered assistant for medical offices, raised a $20 million Series A earlier this month at a $100 million valuation led by Scale Venture Partners, according to a person familiar with the deal.

The healthcare industry is increasingly embracing AI solutions, as seen in the growing adoption of medical scribes from companies like Abridge and Ambience Healthcare. Investors are now betting that patient communication will be the next major area for AI implementation.

Since Assort Health serves small and medium specialty care offices that often have long wait times, fast responses by an AI agent may help these offices lose fewer patients to competing practices.

While Assort Health’s annual recurring revenue (ARR) is only a little more than $3 million, the company is growing quickly, according to two sources. The startup initially focused on orthopedic and physical care offices, but has recently expanded its offerings to other specialties, including Ob-Gyn, dermatology, and dentistry.

Assort Health was founded two years ago by Jon Wang, a former medical student who traded his path in medicine for the world of startups, and Jeff Liu a former Facebook engineer.

Lightspeed Venture Partners and Assort Health didn’t respond to a request for comment.