Tom Callahan, who has led the Massachusetts Affordable Housing Alliance (MAHA) for the last three decades, will step aside from his leadership role at the Dorchester-based non-profit at the end of this year. The group’s board of directors has hired consultants to assist with the transition— including a process to choose his successor —thanks to support from The Boston Foundation.

“MAHA, the entire affordable housing community, and thousands of first-time homebuyers have all benefitted from Tom’s impeccable vision and talents through the years,” said Esther Dupie, MAHA’s board president. “I speak for our staff, board and many external funders and partners who have enjoyed working with Tom. We are enormously grateful to him for his many contributions.”

Callahan has been a key voice in affordable and equitable housing issues in the state and in Dorchester since the 1980s. Under his leadership, MAHA conceived the SoftSecond/ONE program, the nation’s longest running Community Reinvestment Act mortgage program serving over 23,000 homebuyers, over half of them households of color.

MAHA has also established itself as the leading non-profit in Massachusetts in reaching low-to-moderate-income homebuyers and homeowners. More than 40,000 people have graduated from its first-time homebuyer program.

Callahan also led the group’s push to open the Sheridan-Hagins Homeownership Center on Dorchester Avenue, a home for MAHA’s operations and civic engagement efforts.

According to the board, Callahan “leaves the organization in solid financial standing and with a diverse board and staff, both of which are majority female and majority persons of color.”

“I’m so proud to have been a small part of such a committed, supportive team of staff and board members,” Callahan said on Monday. “It has been the honor of a lifetime to have been entrusted by MAHA’s Board to lead this incredible organization that is so singularly committed to building a more just, more equitable housing market for people of color and for first-time and first-generation homebuyers.

He added: “MAHA is strong, healthy and growing. I’m excited to see what it will accomplish in the years to come.”

Gregg Davis of Impact Consults and TSNE MissionWorks has been secured to support the transition in developing a job description for Callahan’s successor, meeting with external stakeholders, and helping the board develop the next steps in the plan.