Here's how the top insurers performed in the 2nd quarter of 2019

The country's biggest health insurers raked in more than $11 billion in profit in the second quarter, particularly as recent mergers and newly-launched business lines began to bear fruit.

The clearest example of this trend is CVS Health, which posted a Q2 profit loss in 2018 but saw profits return to the black and revenues increase significantly following its acquisition of Aetna.

Cigna posted similar results, with its revenues skyrocketing from $11.5 billion in the second quarter of 2018 to $34.4 billion in Q2 2019, thanks in large part to its purchase of Express Scripts, the nation's largest pharmacy benefit manager.

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Ongoing vertical consolidation is making more big-name insurers look like UnitedHealth Group, which remains an industry leader due significantly to its diverse portfolio of services.

CVS just edged out UHG in the second quarter for revenue, earning $63.4 billion, a figure that's nearly $20 billion more than the year before. UnitedHealth posted $60.6 billion in Q2 earnings, an increase year-over-year of about $4.4 billion.

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Molina Healthcare, which has been in the midst of a financial turnaround following significant struggles in 2017, saw a slight downturn in its revenue year-over-year, but executives said they were confident about performance heading into the 2020 plan year and the company did raise its full-year guidance slightly.

Though CVS saw its profits turnaround significantly in Q2 2019, UnitedHealth's profitability far outstripped any of its competitors, both for the quarter and through the first half of the year. On its earnings call, the healthcare giant praised the performance of its Optum subsidiary, which provides a slew of services including pharmacy benefit management, data analytics and healthcare delivery services.

Though Anthem's second-quarter profits took a dip in the second quarter compared to 2018, year-to-date profits are on par with the first half of 2018, with Anthem earning $1.4 billion in the first half of 2019 and $1.6 billion in the first half of 2018.

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Humana's profits went up significantly in the second quarter compared to the prior year quarter and its year-to-date profits are double that of 2018. The insurer's Medicare Advantage plans are a key source of this success, executives said.

Medical benefits membership was consistent between Q2 of 2018 and 2019 (our graphic does not include PBM membership). The main changes were for WellCare Health Plans, which saw a membership increase of nearly 2 million.

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WellCare is set to merge with Centene Corporation in 2020, and Centene said during its earnings call that, pending regulatory approvals, the deal could close earlier than expected and closer to the beginning of 2020.

Molina also saw a slight decline in membership year over year.

Charts contributed by Data Editor Eli Richman.