FEBRUARY

Health carrier giant Anthem gets hacked, as perpetrators obtain data on tens of millions of current and former customers and employees in a sophisticated attack that led to a Federal Bureau of Investigation probe. The information compromised includes names, birthdates, Social Security numbers, street and email addresses and employee data, including income.

PPACA suffers another glitch, this time as the administration sends incorrect tax information to 800,000 people who enrolled in health insurance through Obamacare's federal exchange.

Obama backs tougher fiduciary rules, as industry trade groups vocalize their opposition the controversial DOL fiduciary rule, claiming that it will limit retirement plan participants to seeking advice through robo-advisors because of cost and will thus put them at a disadvantage.

MARCH

Hackers hit Premera Blue Cross, accessing information from about 11 million people, including names, Social Security numbers, bank accounts and medical information.

The Summary of PPACA benefits deadline is pushed back to 2016, with the Department of Labor saying that the feds won't be ready with a template and related document to share with employers until at least January.

WELLNESS INCENTIVE SPENDING sets a record, with employers offering workers a record $693 per employee, up from $594 in 2014 and $430 five years ago, according to the National Business Group on Health and Fidelity Investments.

APRIL

The nation's uninsured rate drops under 12 percent, one of the lowest rates on record, fueled by the Patient Protection and Affordable Care Act.

MAY

Rumors start to fly that an Aetna acquisition is “imminent,” with Wall Street sources saying that the most likely candidate is Humana.

JUNE

Hawaii announces it is killing its PPACA exchange, transferring responsibility for operations to the Department of Health and Health Human Services.

June 25—THE SUPREME COURT rules 6-3 that the subsidies under the Patient Protection and Affordable Care Act will stay, upholding a major tenet of the health care law enabling millions of Americans to keep the tax subsidies that help them buy and afford health coverage under Obamacare. The case represented the biggest legal threat to PPACA since the law was challenged in the Supreme Court three years ago. Had the Court struck down the subsidies, it would have had disastrous effects for the health care market and PPACA. An estimated 6.4 million Americans receive the subsidies in the 34 states that don't have their own exchanges. Reports suggested millions would lose coverage and millions more would suffer from exploding premiums had the government lost in King v. Burwell.

June 30—Willis Group Holdings Plc, the third-largest insurance broker, agrees to merge with Towers Watson & Co. to add consulting operations and help take on larger U.S. rivals.

JULY

July 2—Centene Corp. agrees to buy Health Net Inc. for about $6.3 billion in cash and stock, beginning a round of mergers in the health care space.

July 3—AETNA agrees to buy Humana for $37 billion. Humana's 3.2 million Medicare Advantage members made it a target, since more Americans are turning 65 and becoming eligible for the health program for the elderly and its private insurer-run version. The news has big ramifications, sending brokers, employers and other industry insiders into strategic mode. Shortly after the merger is announced, consulting firm Aon Hewitt finds that nearly half of employers believe this high-level industry consolidation will “result in fewer health plan options for them and their employees.”

PPACA's calorie rule—which requires restaurant owners and major grocers to inform patrons of the calories in their food—is delayed until after the next presidential election. The U.S. Food and Drug Administration sets the date for compliance at Dec. 1, 2016. Meanwhile, legislative efforts are in the works to kill the calorie counting requirement.

Former Medicare chief MARILYN TAVENNER—who helped oversee the difficult implementation of the Patient Protection and Affordable Care Act—is named the new CEO of America's Health Insurance Plans, the nation's most prevalent health insurance lobbying group.

July 15—Religious nonprofit groups must formally opt out of a U.S. Department of Health and Human Services mandate if they wish to avoid a requirement that employers provide health insurance coverage for birth control, a federal appeals court rules.

July 24—Anthem Inc. strikes a deal to buy rival Cigna Corp. for $48.4 billion, wrapping up almost a year of contentious negotiations and potentially creating the largest health insurer in the U.S.

Medicaid and Medicare turn 50.

AUGUST

Missing out? Consulting firm Avalere Health says that 2.2 million exchange enrollees are not receiving cost-sharing reductions despite having incomes that qualify them for the subsidy. That amounts to 27 percent of the 8.1 million enrollees whose income falls between 100 percent and 250 percent of the federal poverty level and who are thus eligible for CSRs.

Social Security turns 80.

NETFLIX announces a new workplace policy allowing its employees who are new parents to take as much time off work as they want during the first year after a child's birth or adoption. The news places the spotlight on paid parental leave, and other big companies—including Nestlé, Dannon, Adobe and Microsoft—soon announce changes and expansions to their own generous parental leave policies.

SEPTEMBER

Cadillac tax opposition heats up as Democratic presidential frontrunner HILLARY CLINTON comes out against the PPACA provision. “Too many Americans are struggling to meet the cost of rising deductibles and drug prices,” Clinton said in a statement in late September. “That's why, among other steps, I encourage Congress to repeal the so-called Cadillac tax, which applies to some employer-based health plans, and to fully pay for the cost of repeal.” She's not the only Democratic candidate on the other side of PPACA: Senator BERNIE SANDERS has opposed the tax since 2009, when he proposed an amendment to PPACA to remove it from the bill.

The Department of Health and Human Services estimates that 17.6 million Americans are insured because of the Patient Protection and Affordable Care Act.

The Eight Circuit Court of Appeals in St. Louis rejects the Obama administration's attempt to work around employer objections to the birth control mandate, ruling that four Christian nonprofits should not have to comply with the controversial Obamacare mandate. It is seen as an apparent set-up for a U.S. Supreme Court ruling.

OCTOBER

Payroll giant Automatic Data Processing Inc. agrees to drop its defamation suit against ZENEFITS, a rapidly-growing Silicon Valley competitor. The lawsuit was borne out of a dispute sparked by ADP's decision to block Zenefits from accessing payroll data for hundreds of mutual clients. Although the two companies are competitors, they also share hundreds of clients who use ADP's payroll processing program along with Zenefits' free employee benefits tools. The news is considered a win for the upstart startup benefits company (and often-perceived broker-threat), valued at $4.5 billion.

NOVEMBER

Congressional lawmakers press the Obama administration on what it is doing about PPACA's failed co-ops. The government-backed alternative health plans have been failing at an alarming speed, as nearly half of the 23 co-ops established under PPACA have gone or are expected to go under by the end of the year.

The Centers for Disease Control announces that the number of uninsured in the United States has dropped to 9 percent, or 28.5 million people.

Nov. 4—The U.S. Department of Treasury officially launches its myRA retirement savings option, which is designed to, in part, fill the void for the more than 50 million Americans without access to a workplace savings plan. For the past year, Treasury has been running a pilot program with about 60 small businesses.

Nov. 6—PPACA is going to the Supreme Court…yet again. The Supreme Court announces it will take up a challenge to Obamacare's birth control mandate, marking the fourth time PPACA has gone before the Court. The challenge was expected due to a lower-court split over the birth control mandate coverage. The birth control coverage requirement has drawn intense legal scrutiny, from both religious charities and colleges such as Notre Dame and Wheaton, since the early days of the law.

DECEMBER

Dec. 15—The end of the period when small businesses can get Small Business Health Options Program (SHOP) exchange plans without worrying about minimum participation requirements. (The prime SHOP enrollment period starts Nov. 15.)