Moss, 24, said she hadn't thought about organ donation until she needed it. Now, she can't stop thinking about it.
"Organ donation means giving life," she said. "I'm living proof, living."
Megan's journey began when she was 15. An athletic student at North County Christian School, she played basketball, volleyball and soccer.
Out of nowhere, her stamina disappeared. The young athlete got out of breath walking between rooms in her house.
"I was in good condition. I'd just finished basketball season and I was starting soccer and I couldn't walk up the stairs without getting out of breath; I couldn't run the laps," she said.
Her doctor first diagnosed asthma and gave her an inhaler. But he took an X-ray to look at her lungs and heart.
Three days later, Megan got a call to visit a cardiologist, "Now."
Megan's heart had grown too large because of a virus, myocarditis.
She had to give up all of the strenuous sports except volleyball, she said.
Except for having to take heart medicines, she lived a relatively normal life after that. She graduated high school, earned her associate's degree in business at St. Louis Community College at Florissant Valley. She started work on her bachelor's degree at the University of Missouri-St. Louis.
She found a good job with benefits working as a hospitality specialist with the Ritz-Carlton Hotel in Clayton.
"She was looking at buying a condo and moving out," said Megan's mother, Kathy Moss. "We were getting ready for the empty nest."
But in November 2009, her stamina faltered.
"I couldn't walk up the stairs without having to stop to get my breath," she said. "I'd come home exhausted from work and have to take a nap."
This time, a cardiologist told her that congestive heart failure had reduced the efficiency of her heart to 13 percent.
Her case was transferred to the Transplant Center at Barnes-Jewish Hospital.
She made it through the holidays, but continued getting sicker. By January 2010, she had lost her appetite and couldn't hold down food.
"I wasn't hungry for anything, so I lost a lot of weight, 12 pounds in the first week."
At 113 pounds, she was back in the hospital. She went on the transplant list on Feb. 2, and went home on intravenous medication.
By April 1, she had to return to the hospital where she jumped to the top of the transplant list.
Open-heart surgery connected her to a machine that pumped blood for her. But her liver and kidneys began to fail.
She developed pneumonia. On April 17, the cardiologist told Megan's parents she was too sick for a transplant, even if they found a heart.
"That morning, I had relinquished her to God," her mother said. "I told the Lord that if her time on earth is done, I release her.
"But I didn't get the sense that that's what God was going to do. Her time was not up; not ready."
The word of Megan's crisis spread. Family and friends came by the hospital. Church members came by. A waiting room was filled with people praying for the young woman who lay in induced sleep in intensive care.
People who had followed a blog written by Megan's father, Wayne Moss, wrote notes of support and faith from Korea, Europe, Africa.
At 9:30 p.m., 12 hours after her parents were told she was too weak for a transplant, their doctor told them their daughter's condition had improved enough for surgery. And a heart was on the way from Texas.
"About 6 a.m., that's my heart birthday," Megan said. "I woke up ... and I had an appetite. I hadn't had an appetite for four months. I could hold food down, and that gave me energy.''
She returned home on May 4, weighing 87 pounds.
Nine biopsies, one a month, haven't turned up any rejection episodes.
She works out three times a week, 30 minutes a day, with a treadmill and workout DVD.
Her job at the Ritz-Carlton in Clayton allowed her to keep her medical insurance if she paid the part she'd pay when she was able bodied.
"They were amazing," she said. "I'm going back to work in a month. They were so good to me."
'YOU'RE NOT INVINCIBLE'
Her message to other young women is, "You're not invincible. I was stopped by heart disease — completely healthy.
"It can happen to anyone. Take care of your body. You can have heart issues when you're young."
But more, she makes pleas for organ donation.
"I never thought about being an organ donor until I needed one. My family didn't think about it until they had a daughter who needed it.
"That's a huge thing in my life," she said. "It can save lives. It saved mine. It's the gift of life."