Maureen Belle learned the hard way that health insurance has its limits.

Diagnosed six years ago with cancer, the 62-year-old Santa Barbara woman battled for years with her insurance company as she fought for her life.

"All the way through the process," Belle said, she and her insurer disagreed over the what was covered and what was not. For example, she recalled, "At 85 pounds, my heart was failing and I had to take medicine that cost $2,000 a bottle, and they questioned it."

Appeals seemed endless. Some were successful, some not, she said. "The appeals process was horrible and I was so sick at that point."

In all, Belle figured that she ended up paying roughly $150,000 out of her own pocket for healthcare and was left with an additional $90,000 in credit card debt.

As a result, she had to sell her home and her business, she said. "I had a successful architecture practice and owned a home and commercial properties. Over time I had to borrow against them to survive and pay my bills and to keep getting medical help."

Some of the struggles that Belle faced several years ago would not be an issue today because of the Affordable Care Act.

Her health plan at the time, for example, had a $1-million lifetime limit, a cap easily reached when fighting cancer and a restriction that the new federal healthcare law has done away with.

Challenging insurance decisions, no matter who pays the bills, can be tricky. To get the job done, experts recommend taking advantage of well-established appeal processes and consumer rights, along with some new appeal rights. Here are some tips:

Know who makes the decisions: your employer or your insurer. The majority of Americans get their health insurance on the job. And most health plans offered by large employers are self-insured. That means an employer contracts with an insurer to administer the plan, and the insurer pays medical claims out of company funds.

Therefore, it's the employer — and not the insurer — that must determine whether it will revise its benefits. Insurance companies can't make coverage decisions for self-insured employers, said Tyler Mason, vice president of communications for Minnetonka, Minn.-based United Healthcare, one of the nation's largest insurers. "The health plan can't say, 'We'll cover it this time.' It's not our money. Legally we can't do it."

Most consumers don't know what kind of health plan they have or who ultimately pays the bills. Helen Darling, president of the Washington, D.C.-based National Business Group on Health, says if you get insurance at work, look to the plan document that explains who administers your benefits.

"By law it has to say it right upfront and prominent," she said. You can also ask your human resources or benefits department or call the number on the back of your health insurance card to inquire about how your plan operates and where to go for help.

Appeal to your insurer. Regardless of how you get your health benefits, the healthcare law gives most consumers the right to challenge their insurance company's decision to deny medical care. Your health plan must provide guidelines about how to go about the appeal process

You're entitled to both an internal appeal with your insurer and then an external review by an independent third party.

Health plans have 30 days to rule on non-urgent cases and 60 days for cases in which payment was denied for medical services that have already been delivered. In urgent situations, health plans must rule within 72 hours of receiving your appeal.

Appeal to your employer. If you are having no luck with your insurer, try the people at work. If the care you need is not covered by your policy, let your human resources department know, particularly if the exclusion seems unreasonable.

"Your employer should know they are paying a lot of money for health benefits that employees are not happy with," Mason of United Healthcare said.

In addition, if a plan was purchased by an employer years ago and hasn't been updated, new evidence that a medical treatment is effective may have since surfaced.

"My advice would be to talk to the people who are administering the plan, especially in your own company. They have the option of deciding to cover it in the future," Darling said.