In 1996, the bearded, long-haired, mysterious Kurt Costner wandered onto the Chancellor estate, jobless and homeless. Katherine gave him a job as handyman at the estate in exchange for room and board. Katherine's best friend Nikki Newman did not trust Kurt, but was reassured of Katherine's claims of his honesty when he found an expensive ring of Katherine's and returned it to her. When Kurt later decided to leave Genoa City, Katherine begged him to stay, saying that she felt as though he were family. Kurt said he felt the same way, but was shocked when Katherine offered him a portion of her estate if he would stay. Kurt declined the offer, and Katherine asked him to shave off his beard for her before he began his new life. Kurt did shave his beard and gather his long hair in a ponytail before he left, accepting some cash and wishes of good luck from Katherine as he walked out her door.
After Ashley Abbott's return from living in Paris, she was cornered and slugged in the face several times by two thugs as she walked through the woods outside Genoa City. Ashley was rescued by Kurt after he had left Katherine's. But the thugs shot Kurt twice, took his cash, and left him for dead next to an unconscious Ashley. Ashley and Kurt were found and rushed to the hospital, where Ashley gratefully arranged to pay all of his medical bills. Katherine identified Kurt whom Ashley had met before, but she did not recognize him without his beard. Trying to impress Ashley who hated her, Diane Jenkins gave blood for Kurt. Ashley became intrigued with Kurt, and determined to find out more about him, she turned to Victor for help.
After being reassured by Katherine, Victor took a liking to Kurt, and while Victor was out of town on a business trip, he asked Kurt to stay at his penthouse to look out for his blind wife Hope and their son Victor Jr. (Adam). Kurt had opened up to Hope about his past and revealed that he had a wife and daughter. Later when Hope told Kurt about her husband Cliff who had been killed in a car accident, Kurt remembered how his wife and daughter had met the same fate. Later, Kurt told Hope about it, and that it is too painful to even remember the good times with his family. Hope told him that running away from the pain would not work either. Ashley got Kurt to admit that he felt responsible because if he had been home, they wouldn't have gone out and gotten in the accident. Kurt refused Ashley's advice to see a therapist, but promised not to leave Genoa City yet. Ashley instead persuaded Kurt to return to Cape Cod with her.
Arriving at his house in Cape Cod, Kurt was flooded with memories of his wife Linda and their daughter. Ashley found and pocketed a letter addressed to Kurt, and left him in the care of his neighbor, Mrs. Miller. The letter turned out to be from his wife Linda, telling Kurt that Linda was having affair with another man, Grant, and that she had left Kurt the night of the accident to be with Grant. After some soul-searching with Hope, Ashley finally decided to turn the letter over to Kurt, but he was missing from Cape Cod. Kurt was secretly back at Katherine's, hiding out from Ashley. Mrs. Miller called Kurt telling him there was a buyer for his house, so Kurt returned to Cape Cod. Just as Mrs. Miller mentioned that Kurt must have found the letter which was missing, Ashley arrived. The potential buyer, Grant Long, looked at the house, but Ashley caught him pocketing a photo in the bedroom. Ashley grabbed the photos of Grant with Linda, but ended up letting him take them. On returning to Katherine's, Kurt pulled out a packet of photos, but when he left the room, Ashley threw the ones of Grant and Linda into the fireplace. Kurt retrieved the photos and confronted Ashley, who finally showed him the letter. Kurt became furious with her for controlling his life and threw her out. After reading the letter, and wondering how he could have been such a fool about his cheating wife, he threw the photos back into the fire.
Ashley called Grant and told him that Kurt knew everything, but Grant foolishly still met Kurt at the Cape Cod house to buy it, where Kurt was waiting for him with a gun. Their heated conversation was interrupted by Grant's wife Rachel. Kurt told Grant their conversation was finished, to take his wife home, then Kurt burned the letter.
Back in Genoa City again, Kurt found Ashley, told her what had happened with Grant, and they ended up in a kiss. Determined to move forward with his life, Kurt began romancing Ashley. One night they went to dinner and were joined by Katherine and Hope. Hope choked on some food, and Kurt performed the Heimlich maneuver on her. It didn't work, so he began CPR. Hope was taken to the hospital, and Kurt ended up performing surgery on her, saving her life. Ashley found out about it, told Victor, whose people discovered that prior to his wife's death, Kurt had been about to become chief of surgery at the hospital in Cape Cod. Victor and the doctors tried to convince Kurt to go back to being a surgeon again, but Kurt was not interested. Instead, Victor, in gratitude to Kurt for saving his former wife Hope's life, rewarded Kurt with the money to fulfill his dream of opening his own free clinic.
Kurt bought a rundown building in a bad part of Genoa City and began renovations. Hope, although blind, volunteered to work at the clinic, and turned out to be quite an asset welcoming and calming patients once the clinic was up and running. Kurt and Hope grew closer, while Ashley became jealous.
One day, a little boy burst into the clinic and took Kurt away to help someone. Kurt arrived at a seedy hotel to find smoke coming out of a room, the room of Sasha Green. Kurt got Sasha out of the room, but she was dead on arrival at the hospital, the FAX she was holding in her hand ending up in Kurt's pocket. The FAX, a receipt from a gossip magazine later became evidence against Phyllis Summers for suspicion of Sasha's murder.
Another time, Kurt arrived at the clinic to find Hope being hassled by a stranger. Kurt chased him off, and told Hope that being blind, it was not safe there for her. Hope pleaded with Kurt to keep her on, that it was the first time in her life that she had been able to do something on her own besides the farm, and that Victor would be full of I-told-you-so's. So Kurt installed a security system and cameras instead.
Still jealous, Ashley pushed Kurt to choose between her and Hope, and was disappointed when Kurt decided he only wanted to be friends with Ashley. Meanwhile, Hope felt guilty that she and Victor Jr. (Adam) were still living with her ex-husband Victor in their own rooms at his penthouse, yet she was sharing kisses with Kurt. Hope and Kurt began looking for a place for her to live since Victor all but ignored her, too busy being romantically involved with Diane Jenkins. Hope confided to Kurt that she worried about what kind of life Victor Jr. would have if he knew he was the son of the great Victor Newman, and suggested that maybe he should never know. After all the secrets he'd been through, Kurt encouraged Hope to tell Victor Jr. the truth about his parentage. He reminded her that no matter if he knew his father or not, Victor Jr. would become the man he was meant to become, and Hope agreed.
Victor's secretary, Connie, called Hope telling her that Victor was back in town and would be home soon. Hope then decided that she and Victor should tell Victor Jr. that very day that Victor was his father. Victor sauntered in as Kurt was saying good-bye to Hope. After Kurt left, Victor told Hope that he had been in Greece on his honeymoon. Hope was livid, and told him that he was the most inconsiderate person she had ever met, and could not believe he would not tell her that he was getting married beforehand. "How do you think this makes me feel?!" she yelled. Hope admitted that she had intended to tell Victor Jr. about his paternity, but now she never wanted him to know. Victor Jr. interrupted them and welcomed Victor home. After Junior left, Hope yelled at Victor, "I'm warning you Victor Newman, do not ever call him 'son' again. And don't you ever violate my wishes. He is never, EVER to know who you really are. If you do tell him, mark my words – there will be hell to pay!"
The next day, Kurt dropped by the penthouse to find out how it went telling Junior about his paternity. Hope informed him that she didn't tell Junior and she never would, and that she and Junior were moving back to the farm in Kansas. They were discussing Diane when Victor came in and overhearing their conversation, told Kurt to butt out. Hope admonished Victor and announced her plans to return to Kansas. Victor offered to help her move, but she said she did not want his help. Victor's eyes narrowed as Kurt offered to help Hope move and settle back in at the farm, commenting that he wanted to see "Hope's world". Hope gratefully accepted his offer. After Kurt left to pack his things and say goodbye to Katherine, Victor wanted to talk with Hope, but Hope told him she and Junior were packed and ready to leave. Despite Victor's protests that there was no rush, Hope insisted that he must want to bring his bride home as soon as possible, so she should be on her way. Victor told her that he would always be there for her, and that he hoped she would not let her stubbornness ever get in the way of asking for his help. Later when Kurt returned, Victor tearfully said good-bye to Hope and Victor Jr. After they left the penthouse, Victor burst into tears.
No mention was ever made of Kurt or what became of the free clinic without him, until 2013, Kurt reappeared again as Nikki Newman's "doctor who makes house calls" who diagnosed her with multiple sclerosis. A few weeks later at Nikki and Victor's umpteenth remarriage the grown up Victor Jr. (now known as Adam) was shot taking a bullet for his father. Upon Adam's arrival at Memorial Hospital, Kurt performed the surgery removing the bullet and bone fragments from Adam's lung.
In conversation with Kurt, Nikki asked him why he was no longer active socially in Genoa City. Kurt told her that he and his wife Liz had been, but that Liz had died two years prior, and he had thrown himself into his work ever since.
Kurt made a couple of appearances as Nikki's doctor in late 2013, has been referred to, but has not been seen since.