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One of the greatest gaps in Medicare coverage is that it does not help to pay for home-based care unless such care is requested by a physician as medically necessary. Medicaid will cover such long-term custodial care for people with little to no income or assets. But Medicaid covers fewer than one in five of the roughly 55 million people on Medicare, leaving the rest to fend for themselves or, for a small group of mostly better-off folks, purchase private long-term care insurance.

Now, it appears that even Medicare’s limited home-based coverage benefits for those with medical needs are also not possible for many people.

Now, it appears that even Medicare’s limited home-based coverage benefits for those with medical needs are also not possible for many people. The nonprofit Center for Medicare Advocacy says it been researching the availability of Medicare-covered home-based care in response to a worrisome and growing volume of complaints from Medicare enrollees that they are being denied home-based care even though they are qualified to receive it and it is covered by Medicare.

Like nearly everything about Medicare, this is a complex topic. But it appears that Medicare is not keen to encourage use of allowable home care benefits. Home care providers don’t much like this benefit either. They don’t make much money on it, and under new Medicare rules, they can actually lose money providing such care.

Let’s begin with the benefit itself. According to the Center for Medicare Advocacy, Medicare will pay for up to 35 hours a week of home-based care — provided by nursing and home health aids — to people who are housebound and for whom such care is prescribed as medically necessary by their doctor or another authorized caregiver. The home health benefit also includes physical, occupational or speech-language therapy.

READ MORE: Does Medicare pay for a home health care provider?

Skilled nursing care is covered on an “intermittent” and “part-time” basis and also for home-based medical social services and for home health aides, who are allowed to perform certain personal services that stem from the patient’s underlying medical needs, but which are not the same as custodial care, which is not covered by Medicare.

These last two coverage categories, while part of Medicare’s benefits, merit only a footnote on the Medicare website. And when Medicare updated its home health care brochure last March, it was full of errors about the nature of available coverage, according to Center for Medicare Advocacy associate director Kathleen Holt.

Holt says the allowable benefits are thus broader than people realize. However, she adds, it looks like it doesn’t matter what’s actually covered, because home health agencies routinely decline to provide even the skimpier services that Medicare publicizes to Medicare enrollees who request them.

Home health agencies routinely decline to provide even the skimpier services that Medicare publicizes to Medicare enrollees who request them.

Significantly, Medicare will only pay insurance claims to home health agencies who are registered and approved by Medicare. Ostensibly to help consumers, it has developed an extensive quality rating system, so consumers can find the most qualified agency. However, there apparently is no requirement that an agency actually provide home health services when Medicare enrollees request them.

The reasons why these agencies turn away business, Holt claims, stem partly from Medicare’s increasing emphasis on paying for health care that actually helps patients get better. This is an admirable goal, but what it means is that home health agencies are rewarded for treating patients who are likely to get better.

Supporting care that cures people, while understandable, is not a requirement Medicare insists on for covering most health care. Therapy that maintains a person’s ability to function, or even that slows the pace of decline, is a perfectly good goal for treatment and one that many older Americans and their families embrace.

However, Medicare and Congress have supported the shift from fee-for-service health care to fee-for-results care. In this situation, home health agencies face a carrot-and-stick financial incentive system based on measurable patient improvement. That’s all fine and dandy, but what this means is that agencies are effectively discouraged from treating people with long-term chronic conditions who may be qualified for services, but are unlikely to get better.

READ MORE: Does my mother qualify for home health care?

This latter group, of course, is filled with growing numbers of older Medicare beneficiaries. Overwhelmingly, such people would like to stay in their homes, and getting home-based care would help make this possible. It’s also well-established by research that home-based care is cheaper than being parked in a nursing home or other institutionalized care facility. On paper at least, Medicare’s home care benefit should be perfect for many of these folks.

While Medicare stresses that the benefit should be considered a short-term solution, Holt notes that it can be renewed for consecutive 60-day episodes of care. So long as a doctor prescribes continuation of such care, Medicare is supposed to cover it.

However, Medicare has been stepping up its surveillance of fraud in home health care services, Holt says, and this has added to home health agencies’ reluctance to accept such Medicare patients. Care lasting beyond 60 days has become a red flag that triggers a fraud investigation by the outside fraud contractors hired by Medicare, she says. Needless to say, home health agencies are not eager to have their Medicare licenses threatened by having a fraud bullseye painted on their backs.

The common response to all of these forces is for home health agencies to either physically or figuratively just not come to the phone when Medicare enrollees come calling looking for care. And this, the Center for Medicare Advocacy has found, is exactly what has happened. In a white paper published last October, the Center for Medicare Advocacy concluded:

Medicare and Medicare Advantage plans are stating that beneficiaries are able to receive up to 8 hours a day and 35 hours a week of home health coverage, however this is not occurring in practice at the home health agencies. Only 8.1% of the home health agencies telephoned were willing to offer, and stated Medicare would cover, [even] 20 hours a week of home health aide services. Although many home health agencies said the number of hours they would provide depended on their assessment of the individual, 52.1% offered 3 or less visits a week, despite contradicting doctor’s orders. Some home health agencies indicated staffing concerns to meet the requested home health aide hours, but many stated a lack of Medicare coverage was the reason for the limited amount of visits a week.

In one specific case in Oklahoma, the Center for Medicare Advocacy found, a person with ALS (Amyotrophic Lateral Sclerosis) theoretically could choose from among 48 Medicare-licensed home health agencies for care where they lived. A patient’s representative got through to 42 of the 48 agencies and was told that only three of the 42 would even consider evaluating the person for care. Further, none of the agencies would consider providing the person more than three hours of home health aide services a week, even though the person’s doctor had prescribed 20 to 28 hours of care a week as medically necessary.

I reached out to Medicare for comment on this situation. The agency’s public information office had not responded after several days.

READ MORE: How to hire in-home help when your aging parents don’t want to move

Is legal for employers to pressure their employees to drop workplace health insurance? Phil Moeller answers that question and more in tomorrow’s forthcoming Q&A.

Editor’s note: This article has been updated to clarify and expand the description of Medicare’s home health benefits.