Matt is a strait-laced lawyer who became gradually close to Donna Martin, Kelly Taylor, and the rest of their friends, eventually becoming a resident at the Walsh House. Matt had a pleasant but generally serious personality, though he is sometimes prone to joke with the others. Matt and Kelly eventually began dating, though their relationship was complicated by the return of Dylan McKay, one of Kelly's ex-boyfriends, and by the return of Lauren, Matt's wife. Lauren had been in a mental hospital in New York City suffering from schizophrenia. She reunited with Matt temporarily while she was on medication, but had to return to New York when she discovered that the drug was killing her. She filed for divorce shortly thereafter, asking Kelly to look after Matt for her.
Matt and Kelly eventually became engaged, but the issue of Dylan continued to come between them. While under the influence of LSD at a party, Matt slept with another girl, causing a further distancing between him and Kelly as he hid the truth from her until the final episode.
During season ten, Matt agreed to be a sperm donor for his brother and sister-in-law against Kelly's wishes. After his brother is killed in a car accident before the child is born, Matt toys with the idea of moving to NY to be a father to his child.
Eventually, Matt and Kelly's engagement ended, as she admitted that she still had feelings for Dylan. She insists that he surrogate-fathered Juliane Durning's child and, at the end, he chooses to return to New York City to be with his daughter.