When the companies are the same type of business, it is called horizontal consolidation, not vertical integration. Vertical integration is a company buying its supplier or its customer.
Yes, I started off my comment referring to Anthem purchasing Aspire Health the previous commenter referred to which is vertical, but then I abruptly transitioned to talking about horizontal integration. I was trying to convey that because of the horizontal integration, the next step is to go vertical like insurance is doing with providers and PBMs and pharmacies.