Aetna Inc. submitted bids with the Centers for Medicare & Medicaid Services in June to help it grow its share of the Medicare population.

Speaking on a second-quarter earnings call, Chairman and CEO Mark Bertolini said the health insurer hopes to capture approximately 60% of the Medicare population in 2018, up from 56% in 2017. By 2020, that figure could be in the 80% range, Bertolini said. Aetna's goal is to accelerate its geographic expansion in 2019 and beyond to serve more of this growing population, he added.

The move to bolster Aetna's Medicare presence is part of the company's strategy to build capabilities that will support growth in the absence of major horizontal acquisition opportunities. Through these initiatives, Aetna hopes to achieve mid- to high single-digit top line growth and low double-digit adjusted EPS growth over time.