Last-minute shoppers endured long waits at the MNsure call center as the state's health insurance exchange, insurers and consumer advisers all reported heavy traffic before Monday's deadline for January coverage.

Callers to MNsure on Sunday waited an average of nearly 50 minutes on hold, according to figures reported Monday by the government-run exchange. By 3 p.m. on Monday, callers were waiting an average of 53 minutes.

The Sunday figure was the longest average daily wait during the current open enrollment period, which started Nov. 1.

"While 50 minutes is certainly excessive and diminishes the customer experience, the reality is the lengthy wait times are due to the significant increase in number of individuals enrolling this close to the deadline," said Dan Schuyler of Leavitt Partners, a Salt Lake City-based consultant that follows the new health exchanges created by the federal Affordable Care Act.

Minnesota launched the MNsure exchange two years ago to implement the health care law, which requires almost all Americans to have health insurance or pay a tax penalty.

It's an option for the roughly 300,000 state residents who purchase private health insurance policies and don't get coverage through an employer or the government.

On Sunday, MNsure saw about five times the regular call volume for a typical Sunday, said MNsure spokesman Shane Delaney.

"This is the first time we've ever had the day before a deadline being a weekend," Delaney said. "We just under-forecasted what we thought the call volume would be."

By noon Monday, the average wait was only slightly better at more than 48 minutes. Even so, about 72 percent of calls Monday morning were being answered within five minutes, Delaney said.

"Some people are waiting longer than others to get a call answered, depending on the responses to prompts when calling us," he wrote in an e-mail.

The average waits on Sunday and Monday were longer than daily averages reported by MNsure during last year's open enrollment period, according to Star Tribune records. But they remain far shy of the troubles two years ago, when callers to MNsure on some days waited an average of two hours.

MNsure and insurers expect that more people will enroll in coverage through the exchange for 2016, because premiums in the individual market are set to jump an average of 41 percent.

"The phones are busy, and hold times getting through to MNsure to help people enroll are over an hour," wrote Wendy Wicks, a spokeswoman for Minneapolis-based UCare, in an e-mail Monday afternoon. UCare is one of four health insurers selling individual insurance policies through MNsure.

Tax penalties under the Affordable Care Act get bigger in 2016, with the California-based Kaiser Family Foundation estimating the average penalty will grow 47 percent to $969.

Consumers can avoid penalties by purchasing coverage through MNsure or directly from health insurers who compete in the "off-exchange" market. Federal tax credits that discount premium costs are available to people at certain income levels, but only when they buy through a government-run exchange.

Monday also was the deadline for purchasing individual policies directly from Eagan-based Blue Cross and Blue Shield of Minnesota, which is currently the largest insurer in the state's individual insurance market.

Wait times on Monday at Blue Cross were offset somewhat due to a new callback technology that the insurer added earlier this year, said Jim McManus, a Blue Cross spokesman. Instead of waiting on hold, people can opt for a return call from Blue Cross.

"We're seeing a higher volume of calls, which is always the case on the last day to sign up for coverage," McManus wrote in an e-mail.

Thursday will be the deadline for buying off-exchange policies from Bloomington-based HealthPartners and Minnetonka-based Medica.

At St. Paul-based Portico Healthnet, health insurance navigators were busy Monday helping people enroll in both public programs as well as private coverage through MNsure, said spokeswoman Meghan Kimmel.

"We have been very busy all of December," Kimmel said. "We are prepared for a very busy January, too."

Open enrollment continues until Jan. 31. People who purchase policies by Jan. 15 will have coverage that starts in February, while those buying in the second half of January will have coverage that starts in March.

After Jan. 31, people can enroll in private coverage only in special circumstances.

Consumers sign up for the state's Medical Assistance and MinnesotaCare programs through MNsure, too. People with qualifying incomes can enroll in the programs at any time.

Christopher Snowbeck • 612-673-4744

Twitter: @chrissnowbeck