Andreessen Horowitz has led the $300 million Series B, with participation from Premji Invest and Uprising. : Devoted Health, a Waltham, Mass.-based insurance startup, has raised a $300 million Series B and is enrolling to its Medicare Advantage plan members in eight Florida counties. The company, which helps Medicare beneficiaries access care through its network of physicians and tech-enabled healthcare platform, has raised the funds from lead investor Andreessen Horowitz, Premji Invest and Uprising. Devoted’s founders are brothers Todd and Ed Park — the company’s executive chairman and chief executive officer, respectively.