Its performance, along with UnitedHealth's report from last week, will give analysts a better sense for any trends that may be forming in the managed care sector.
WHAT'S EXPECTED: Analysts expect, on average, earnings of $1.33 per share on $8.83 billion in revenue, according to FactSet.
LAST YEAR'S QUARTER: Aetna earned $490.4 million, or $1.30 per share, as revenue excluding capital gains fell 1 percent to $8.4 billion. A charge for an early retirement program hurt the insurer's performance. But Aetna also saw a $117million gain in last year's third quarter because leftover claims mostly from the second quarter came in lower than expected.