Owners of assisted-living facilities are lobbying lawmakers for authority to provide several highly sought medical services — a campaign that is sparking concern among patient advocates and dividing the industry.

Unlike nursing homes, which provide round-the-clock medical care by nurses, assisted-living centers are designed and regulated in Massachusetts as private apartments that offer assistance with daily activities, such as bathing, cooking, dressing, and managing medications. Such facilities are home to roughly 14,000 residents in Massachusetts.

Proposed legislation would allow assisted-living facilities to provide limited medical services that include injections, catheter replacement, applying medication and sterile dressing for wounds and skin problems, and administering oxygen to patients with serious ailments.

Supporters say the changes would allow a growing number of elderly residents to live more independently and avoid nursing homes by receiving medical attention in their own assisted-living apartments.

But opponents worry the Executive Office of Elder Affairs, which regulates the state’s 241 assisted-living centers, may not have the capacity to safely monitor the proposed medical care. The agency has struggled in the past to address consumer complaints because of a lack of staff.

Many states regulate assisted-living residences as health care facilities. Massachusetts remains among a handful that still consider the facilities more similar to apartment living. While current state rules bar the facilities from offering medical procedures, assisted-living residents can hire visiting nurses to provide more skilled care.

But Richard Moore, president of the Massachusetts Assisted Living Facilities Association, said some residents have been having a hard time finding visiting nurses because of staffing shortages.

“We have had people developing a need for a particular service, finding it could not be provided by the assisted living and could not get an outside provider to do it, and so they ended up going to skilled nursing [homes],’’ said Moore, who before joining the trade association was a state senator from Uxbridge and an architect of the state health care overhaul.

James Fuccione, director of a trade association that represents home care companies, said he was unaware assisted-living residents were having problems finding available help. Fuccione’s Home Care Alliance of Massachusetts represents companies that offer a wide range of services, including nursing, home health aides, and hospice care.

The proposed legislation would probably divert business away from Fuccione’s members, a point he acknowledges.

“We are trying to look out for the best interests of our home health agencies and the people who receive care,’’ he said.

Fuccione said that if assisted-living facilities are allowed to offer medical services, state oversight of the industry should be strengthened and shifted to the Department of Public Health, which regulates nursing homes and other health care facilities.

“If you are a facility providing some degree of nursing care, then you should be overseen by the state entity that could monitor quality and safety of that care,’’ Fuccione said.

The Massachusetts Senior Care Association, which represents assisted-living facilities and nursing homes, recently raised similar concerns in written testimony it submitted to lawmakers.

The 1994 law that established state oversight of assisted-living facilities envisioned residents moving on to nursing homes as they became more frail. But many elders who once would have moved when their health declined are instead choosing to remain in assisted living, often because the cost is significantly less.

The state elder affairs agency last year updated some rules to reflect the shift in population, mandating expanded training for assisted-living facility workers and requiring detailed emergency evacuation plans.

But regulators backed off one of the most hotly contested provisions, which would have prohibited assisted-living facilities from accepting residents, or allowing them to remain there, if they require more than 90 consecutive days of skilled nursing care provided by a visiting nurse.

The agency has not taken a position on the proposed law to allow medical services in assisted living, and Elder Affairs Secretary Alice Bonner was unavailable for an interview.

Spokeswoman Martha Waldron said in a statement the office has a five-person team that checks and re-certifies facilities every two years and one full-time ombudsman who fields and investigates complaints.

The office used to have two ombudsmen. Waldron declined to say whether the agency believes it has sufficient staffing. She said the office has erased its backlog of complaints, which plagued the agency in late 2014, by using an electronic system that allows for better tracking.

Senator Patricia Jehlen, a Somerville Democrat who chairs the Legislature’s Joint Committee on Elder Affairs and sponsored the proposed legislation, said she supports the concept of more medical services in assisted living. But she said the questions raised in recent weeks have convinced her the issue is more complicated than she had imagined.

And, she said, she worries the elder affairs agency does not have sufficient staffing to effectively monitor more services.

The Assisted Living Facilities Association is working on a revised proposal to address concerns and aims to have it completed before July, said Moore, the group’s president.

Some elder advocates say the new version should include safeguards to assure consumers understand the differences between assisted-living facilities and nursing homes. Too many families do not realize that assisted-living residences are not medical facilities, said Susan Antkowiak, vice president of programs and services at the Alzheimer’s Association of Massachusetts and New Hampshire.

“We’re advocating that there be clarity and full disclosure, so the consumer would understand what this [assisted-living] model includes and what it doesn’t,’’ Antkowiak said.

Kay Lazar can be reached at Kay.Lazar@globe.com Follow her on Twitter @GlobeKayLazar.