When Congress created new assistance programs for veterans' caregivers four years ago, the idea was to make caring for an injured loved one easier. But for many it has just become another headache, officials say.

Caregivers face a host of disparate eligibility requirements and lengthy registration waits despite the obvious financial and emotional support they provide, researchers told members of the House Veterans' Affairs Committee on Wednesday.

They're pushing for better coordination of Defense and Veterans Affairs Department offerings and an expansion of those programs, to ensure support services for all military and veterans caregivers.

"No one-size-fits-all approach is going to work here," said Rajeev Ramchand, a researcher with the Rand Corp. "These programs need to be adapted ... for more veterans, for aging issues that will develop."

VA officials say they are making progress, with a caregiver coordinator in every VA hospital and a comprehensive national program for caregivers.

Under the new programs, caregivers can receive formal training and assistance to provide for their injured veterans' medical needs, and medical coverage for themselves if other health care isn't available. Caregivers of Iraq and Afghanistan war veterans can also receive a stipend for their home care work.

The department has about 18,000 caregivers in its assistance program, more than four times the demand VA officials originally estimated. Government Accountability Office researchers said that has led to multimonth waits for some new applicants, and frustration with the application process.

Dr. Maureen McCarthy, VA's deputy chief of patient care services, said some of that can be blamed on program limitations. Veterans must have an injury — not just an illness — to be eligible for caregiver stipends. Officials must vet both the caregiver and veteran for the program, further delaying the process.

Lawmakers on the panel said they'd consider making changes to ease those issues.

Outside advocates have also pushed for the stipend program to be expanded to veterans of all eras, but committee members were skeptical that VA could handle that change given its current difficulties. In fiscal 2014 alone, the caregiver support programs cost about $350 million.

Rand estimates there are about 5.5 million military or veteran caregivers in the country, with about 20 percent (1.1 million) looking after veterans of the current wars. They also estimate their work saves the government about $13 billion annually, through the free medical services and emotional support they provide.

More than half of those surveyed by their researchers had no support network to provide answers to medical questions or outside assistance. Ramchand said that's unconscionable, given the service they provide to the country and their loved ones.