The leader of one of the U.S.’s largest health insurance agencies—who has been saying for months that ObamaCare is on the ropes-- said Wednesday that statistics indicate that the law has now entered a “death spiral.”

Aetna’s CEO Mark Bertolini told The Wall Street Journal that the health law’s market is nearing failure because healthier people have dropped out while premiums continue to climb.

Health insurer Humana announced it is leaving the law’s public insurance exchanges for next year as it regroups after ending its proposed combination with rival insurer Aetna. Humana Inc. covers about 150,000 people on exchanges in 11 states.

Aetna Chairman and CEO Mark Bertolini on why Aetna and Humana ditched their merger plans: https://t.co/AJziRPuxLe — Wall Street Journal (@WSJ) February 16, 2017

The Trump administration took steps Wednesday intended to help calm jittery insurance companies and make tax compliance with former President Obama’s health law less burdensome for some. The administration's actions signal a change in direction.

For consumers, the proposed rules mean tighter scrutiny of anyone trying to sign up for coverage outside of open enrollment by claiming a "special enrollment period" due to a change in life circumstances such as the birth of a child, marriage, or the loss of job-based insurance. Also, sign-up season will be 45 days, down from the current three months.

Aetna Chairman and CEO Mark Bertolini on why he thinks the Affordable Care Act is untenable: https://t.co/Xb3Q6vrNII — Wall Street Journal (@WSJ) February 16, 2017

For insurers, the curbs on special enrollment periods are a big item. The industry claimed that some consumers were abusing special enrollment by signing up when they needed expensive treatments, only to drop out later.

Aetna is considering reducing its presence in the markets set up by ObamaCare, Bloomberg reported. The insurer already reduced its footprint in four states after losing $450 million last year.

Insurers also would gain more flexibility to design low-cost coverage tailored to younger people. In another move aimed at consumers who move in and out of coverage, insurers would be able to collect back premiums from customers who had stopped paying, then tried to sign up again for another year.

Separately, the IRS is backing off from a tighter approach to enforcement that was in the works for this tax-filing season.

Under the law, people are required to have health coverage or risk fines from the IRS -- a penalty usually deducted from a taxpayer's refund. That underlying requirement remains on the books, and taxpayers are still legally obligated to comply, the IRS said.

But the agency is changing its approach to enforcement. Originally, the IRS had planned to start rejecting returns this year if a taxpayer failed to indicate whether he or she had coverage. Now the IRS says it will keep processing such returns, as it has in the past.

Many of the law's supporters consider the coverage requirement essential for nudging younger, healthy people into the insurance pool to keep premiums in check.

Hours after his inauguration President Trump signed an executive order directing federal agencies to look for ways to ease requirements of the 2010 health care law.

The IRS said in a statement that it is following through, but "taxpayers remain required to follow the law and pay what they may owe."

The Associated Press contributed to this report