Amazon sent shockwaves through the health tech sector when it announced plans to acquire primary care network One Medical for $3.9 billion over the summer, as retail-focused companies continue to pursue primary care M&A. However, San Francisco-based One Medical, which operates more than 200 medical offices across 25 markets, was making news well before the acquisition as it expanded its business beyond the healthy, wealthy well and into the riskier — but potentially more lucrative — Medicare environment last year.