Several of Jessica's family members have advanced degrees, but when they all put their heads together they still couldn't figure out how to compare Medicare plans for her ailing father.

"The Medicare book is like 100 pages," said Jessica, who asked for her real name not to be used, to avoid endangering her father's health insurance appeal. "An elderly person isn't able to go through all that."

Dec. 7 is the deadline for open enrollment for Medicare, the government health insurance program that is largely for covering seniors over 65. Starting in 2019, patients can switch between Medicare Advantage plans from Jan. 1 to March 31.

In recent months, the White House has been encouraging seniors to consider leaving the national health insurance program and sign up for the privately run Medicare Advantage.

"Get more benefits for your money," read one message sent by Medicare to seniors who had signed up for updates to the government website. "See if you can save money with Medicare Advantage," read another, sent the following week. "You may be able to lower your out-of-pocket costs while getting extra benefits, like vision, hearing, dental and prescription coverage," one email explained.

This year, patients have several new options to consider and can look forward to average premiums declining.

But considering the options can be daunting, and not without pitfalls. That's why for patients and their families it's important to know about several free and less-advertised public services for weighing their choices, and to read the details closely.

One of the best tools for comparing plans is hiding in plain sight on the official government website at medicare.gov/find-a-plan, said Kim Lankford, a Kiplinger's Personal Finance contributing editor.

Type in your zip code, prescriptions and dosages, and the system will show you all the plans and estimate the out-of-pocket costs. "It does all the analysis for you," Lankford told NBC News.

For those who are less computer savvy or would like some extra help, try SHIP, the State Health Insurance Assistance Program. Each state gets funding from the federal government to give free health coverage consulting for Medicare patients. Elderly people can come to local offices to get free one-on-one counseling for navigating their plan options. Start finding your nearest outlet at shiptacenter.org.

Since Jessica and her family weren't aware of these options, they began Googling and clicking on internet ads. They didn't get answers. Instead they started getting robocalls from health care providers.

Meanwhile, they were battling to get their father into a rehab facility. Her father's insurance, a Medicare Advantage plan, was resistant, she said.

Medicare Advantage plans are private insurers contracted by Medicare to provide your health benefits. Jessica's parents had signed up for this one about 20 years ago, when they were healthy, based on the pricing recommendation from a friend.

While the majority of patients are covered by traditional plans, about one-third are in Medicare Advantage plans, a number that has risen steadily from 13 percent of patients in 2004, according to the Kaiser Family Foundation.

Medicare Advantage plans are sometimes seen as preferable because they can have lower premiums, but with that can come more limited coverage and higher out-of-pocket costs. Other patients choose to get traditional Medicare and add supplemental drug coverage.

"People tend to like Medicare Advantage plans because they tend to work like plans they had with their job," said Kristine Grow, senior vice president of communications for AHIP, a DC-based trade organization representing health insurance plans. "Some have services above and beyond traditional Medicare, have prescription drug coverage already baked in, and cover both primary care and hospitalizations."

This year, patients will have even more choices for Medicare Advantage, as well as Medicare "Part D" prescription drug coverage, said Lankford. But it's important to not get stuck on one number.

"Don't just look at premiums, look at total costs," she said.

While average premiums are going down for Advantage and Part D this year, some plans might charge higher co-payments or have smaller provider networks.

The monthly premiums can even be as low as zero dollars. But when it comes time to use them you can find that access is really limited or procedures are denied. Make sure to read the fine print and make sure that you're getting a good deal based on your needs. Don't discount calling up the health plan directly to help navigate options, said Grow.

And when dealing with brokers, "there are some thing to do to stay safe," she added. For instance, check their broker certification.

"If you if you get a cold call from a company you don't recognize and want to go straight to the source, you can go straight to source," said Grow.

Jessica now wishes she'd been more involved in helping her parents make their coverage choices two decades ago.

"It's a lot of bureaucracy trying to care for a loved one," she told NBC News.