Update: 8 state exchanges: Enrollment *up* 3%! 8 carriers: Enrollment *down* 8%!

Last week I noted that according to the official enrollment data for 8 of the state-based exchanges, effectuated QHP enrollment as of September 30th had actually increased 2.7% since June 30th (or, at worst, down only 0.1% if you don't include Massachusetts, which has special circumstances):

If this is representative nationally, it suggested that total exchange QHPs are as high as 10.1 million or, at worst, down only around 12,000 people since June.

However, I also reported that according to the quarterly financial reports of 5 major insurance carriers (Aetna, Anthem, Molina, Centene and UnitedHealthcare), effectuated exchange enrollment had decreased by around 8.3% since June:

Since these 5 companies only represented around 28% of all exchange QHPs as of June, it's entirely possible that many of the "missing" enrollees have simply shifted over to competitors, but total enrollment likely has dropped somewhat (which is exactly what the HHS Dept. is assuming; they've projected that the number will be down from 10.0 million as of June to around 9.1 million in December).

Today, I was able to add a sixth carrier: HealthNet. Their total individual market enrollment for Q1, Q2 and Q3 of 2015 were reported as 360,000, 350,000 and 334,000 respectively. Unfortunately, they weren't able to break those numbers out between on and off-exchange, but they did say that in general around "75-80%" of their individual market is on-exchange this year. Thus, assuming 77.5% of each number is via the ACA exchanges, it breaks down as follows:

This nudges the overall national drop a bit, to around a 7.9% drop, based on companies holding around 31% of the total.

It's still possible that many of the "missing" enrollees have shifted to other exchange competitors, but the more companies which report drops, the less likely this is to be the case.

This isn't necessarily a bad thing, of course, if those people moved to Medicare, ESI, etc etc., but it does suggest that attrition is higher than I've been thinking (I assumed that exchange enrollment will still be around 9.7 million as of December, vs. HHS's 9.1 million).

Meanwhile, Cigna and Humana are two of the other large carriers expected to release their quarterly numbers this week; I'll see if I can extract exchange data from them as well.

UPDATE 11/6/15: OK, both Humana and Cigna have chimed in as well...and it's still looking like around an 8% drop overall:

• Humana provided exact ACA exchange-based numbers for each quarter; they reported a 9.2% drop from June 30 through September 30.
• Cigna doesn't distinguish between on- and off-exchange, but given the other 7 carriers, this seems to be proportionately reasonable: A 3.6% drop from June 30 to September 30:

Collectively, these 8 insurance carriers represented nearly 40% of the total June exchange enrollments (39% assuming around 25% of Cigna's numbers are off-exchange). IF these numbers are representative of the other 60% of the exchange market, as of September 30, effectuated ACA exchange enrollment should have been down to roughly 9.2 million people nationally.

This is slightly higher than the HHS Dept's estimate of 9.1 million...except that number was supposed to be as of December, not September.

However, the increase in the 8 state exchanges at the top of this entry still suggest that a good portion of the "missing" 312,000 enrollees were replaced by additional enrollees in other carriers.