Roswell Park Cancer Institute is counting on a renewed federal tax credit to fill in the remaining $4 million funding gap for its planned $42 million Clinical Sciences Center that it hopes to break ground on this spring.

The cancer hospital has been raising money since June 2011 for the narrow, 11-story facility, to be located at Michigan Avenue and Carlton Street, on the edge of the Buffalo Niagara Medical Campus.

Through a combination of major gifts, routine community fundraising and the hospital’s own budget, Roswell Park has amassed $38 million so far, putting it just short of its goal.

Thursday, officials said that it will turn to the federal New Markets Tax Credit program to finish the job. That program, which nearly expired in December, is designed to spur business investments in urban-development projects by allowing individuals or corporations to get a tax credit in exchange for capital investments.

The planned use of the tax credit, which investors would purchase from Roswell Park, is designed to get the cancer hospital over the hump in its capital campaign, without having to divert time and resources away from other projects to raise additional money. The hospital will still need to raise an additional $10 million later to build out the facility.

“I’m very optimistic about the project, so we would have found a way,” said Dr. Donald L. Trump, Roswell Park’s president and CEO. “The New Markets Tax Credit is a real final push to allow this to go in a way that’s most productive for the institute.”

Roswell Park executives announced their new strategy in conjunction with Sen. Charles E. Schumer, D-N.Y., who has championed the tax credit as a way to help development initiatives in upstate New York. Schumer fought at year’s end to save the expiring tax credit from the budget chopping block as part of the “fiscal cliff” deal, and is already lobbying to get credits allocated to Roswell Park.

“The hospital’s done a great job, but the project still needs some critical funding,” Schumer said at a news conference. “There’s an opportunity today for the federal government to help get that plan over the finish line.”

That way, the hospital can move forward with the 142,000-square-foot project to enhance cancer treatment and research, strengthen the Medical Campus and create hundreds of jobs in downtown Buffalo. “Roswell Park and its supporters are on the brink of a tremendous plan that will improve health care and cancer treatment in Western New York,” Schumer said. “It’ll be built on cutting-edge research and create hundreds of jobs in the process. A win-win-win. What could be better?”

Most of the funds so far have come through the combined efforts of the Roswell Park Alliance Foundation, the hospital’s fundraising arm, and its $25 million Making Room to Save Lives Campaign, the community fundraising effort geared toward the new facility.

The major campaign, which was spearheaded by Scott R. Bieler and Donna M. Gioia, included 10 gifts of $1 million each from Bieler and nine other families. In all, 435 donors contributed. The campaign closed in December, after New Era Cap donated $1.5 million to meet the target. Community events, such as the Ride for Roswell, with 8,000 participants, also contributed, officials said, and the hospital allocated funds from its own budget.

“Roswell Park Cancer Institute is an important pillar in our community,” said Bieler, who is also president of West-Herr Automotive Group. “Together we will build a greater Roswell Park, to expand facilities and programs for compassionate integrated care for cancer patients and their families.”

Under the New Markets program, the Treasury Department awards credits to community development organizations around the country, which then choose projects to allocate them to. Investors can buy those credits by investing capital in the projects, but it’s not dollar for dollar. Roswell Park is applying for $25 million in credits that will translate into $4 million in cash.

Schumer is personally lobbying several community development entities to provide the credits to the hospital. Already, the National Development Council has “pledged to work with me to get the Roswell project done,” and Schumer is also reaching out to a division of Wells Fargo & Co. and others.

The new initiative will cap off a capital campaign to support Roswell Park’s first new construction in six years, since the opening of its $79 million Center for Genetics & Pharmacology, which opened in 2007 on Virginia Street, next to the University at Buffalo’s New York State Center of Excellence in Bioinformatics & Life Sciences. It’s also one of the newest and biggest additions to the Medical Campus.

Plans call for the new facility to house both treatment and research space, strengthening Roswell Park’s ability to not only serve the community with medical care, preventive services and patient education, but also attract leading clinicians and researchers.

The new facility will expand Roswell Park’s breast cancer center, providing increased capability for both screening and treatment, including enabling more community-based screening. It will house survivorship, adolescent and young adult programs and a patient education program. The facility will also double its chemotherapy infusion space, so it can serve 130 patients instead of the current 70.

The building also will include advanced office and research space for clinical scientists, who will see patients in the center but also conduct research in their offices in the same building, Trump said.

The institute expects to create more than 200 construction jobs and more than 340 full-time jobs in the next six to eight years, in all areas of such a facility, ranging from physicians, midlevel practitioners and nurses to building staff. Trump pledged to make “access to employment at Roswell Park more and more available to more of our neighbors in the community,” with job fairs and résumé workshops.