The number of Obamacare enrollments for top health insurer Aetna is plummeting, according to a report from Investor’s Business Daily.

Aetna’s enrollment reached 720,000 by May 20, after the final end to the the extended open enrollment period. But by the end of June Aetna had less than 600,000 paying customers, IBD reports, and the company expects paying customers to fall to “just over 500,000” by the end of 2015. That would be a drop of just under 30 percent from the May sign-up numbers — the last time the Obama administration released its official Obamacare enrollment tally.

Aetna’s reported drop-off rate appears to be more extensive than other companies. Cigna reported that between both its exchange customers and those in the private individual market, it expects to lose around 20,000 paying customers throughout the year, out of 300,000.

The federal government released monthly enrollment reports throughout Obamacare’s first open enrollment period, but stopped offering details when widespread enrollment ended in mid-May. But Americans with certain qualifying life changes can still sign up for coverage on an Obamacare exchange at any time, and customers are regularly dropping coverage as well. (RELATED: Survey: Obama Admin Stays Silent On Obamacare Data)

But the administration refuses to give out any details on the total enrollment and has never released information on the percentage of Obamacare sign-ups that followed through and paid their first premiums to activate their coverage. Most insurance companies have reported that by the end of the open enrollment period, only around 85 percent of those who signed up on Obamacare exchanges ended up buying a health insurance plan.

On top of those who initially paid for their coverage, experts agree that the exchanges are seeing a large amount of churn — new customers are constantly enrolling for a number of qualifying reasons — turning 26 and being kicked off a parent’s health plan, getting married, and losing a job are all reasons Americans can sign up for coverage anytime.

At the same time, many others are dropping the coverage they bought on the exchange. Some may find new employer coverage or substitute an off-exchange plan; others may not be able to afford to continue paying their premiums. (RELATED: Community Centers Warn Poor Won’t Keep Paying Obamacare Premiums)

But while an initial tally of sign-ups is the only number the administration has released, companies are still waiting to see whether ongoing sign-ups are replenishing the ongoing Obamacare dropouts.

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