U.S. health care spending grew 3.6% in 2013, capping a five-year stretch of historically low growth, the Centers for Medicare and Medicaid Services said in December.

That's good news for health care payers, but is the slowdown — which was the smallest increase since 1960 — sustainable?

What we're seeing is “a slowing down of what was perhaps unsustainable” increases in the cost of health care, said Elise Gould, senior economist and director of health policy research at the Economic Policy Institute, a Washington-based think tank.

Health care spending rose at or below 4.1% per year from 2009 through 2013, CMS reported in the journal Health Affairs in December. That's a far cry from the double-digit spikes of the late 1980s and early 1990s and the high-single-digit increases of the early 2000s.

Still, increases in health care spending outpaced the U.S. inflation rate of 1.3% for the 12 months that ended in November.

“We've talked about it being a new normal, that the days of double-digit inflation are unlikely to return soon” for health care prices, said Mike Thompson, New York-based principal and health care practice leader at PricewaterhouseCoopers L.L.P.

Mr. Thompson said the growing consumerism movement, hastened by the Patient Protection and Affordable Care Act's upcoming 2018 excise tax on high-cost health plans, will factor into controlling future health spending.

Charles Roehrig, vice president and director of the Center for Sustainable Health Spending, a research arm of Ann Arbor, Michigan-based nonprofit health care consultant Altarum Institute, said sluggish growth in health care prices and other effects of the recession were key contributors to the five-year slowdown in health care spending.

He noted that the ACA's productivity adjustment factor to ratchet down Medicare payment rates to hospitals is having a wider effect because commercial payers are following Medicare's lead and negotiating lower rates, too.

A broader move to value-based contracting, which rewards providers for efficiency and outcomes, also could be a factor, Mr. Thompson said.

“I think some health systems are anticipating that's where it's going and they need to start turning the ship now,” he said.

At the same time, prescription drug expenditures are pulling health care spending higher. Retail drug spending rose 2.5% in 2013 vs. 0.5% in 2012, CMS reported. Year-over-year price growth jumped 5% in 2009 and has varied widely over the five-year period.

With fewer brand-name medications going generic and the blockbuster hepatitis C drug Sovaldi expected to ring up $10 billion to $11 billion in 2014 sales, prescription drug spending alone “is driving the rate of increase in national health expenditures up a few tenths of a percent,” Mr. Roehrig said.

Analysts already see an uptick in spending in the near term. The U.S. Census Bureau's Quarterly Services Survey, for example, found that health care spending increased 5.4% in the third quarter of 2014 vs. the same three-month period in 2013. And through the first nine months of 2014, health spending rose 5% compared to a 3.6% growth rate for all of 2013.

George Miller, a fellow at the Altarum Institute, said a gradually improving economy and more people using their new coverage under ACA are “certainly putting upward pressure on spending.”

The longer-term pace of health care spending depends on factors that include how quickly the economy recovers, whether inflation returns and if the health care reform law remains intact as Republicans take control of Congress, analysts said.

In a separate analysis in the September issue of Health Affairs, CMS actuaries predicted health care spending will increase an average of 6% per year between 2015 and 2023, fueled by ACA coverage expansions, economic growth and an aging population.

Benefit managers planning for 2016 and beyond welcomed news of the 2013 deceleration in spending but continue to wrestle with cost issues, said Karen Marlo, a Washington-based vice president at the National Business Group on Health.

Their thinking is “that's great, but I still have to control costs for my company; my CEO still wants me to bring health care costs down,” Ms. Marlo said.