CHICAGO, March 20 (Reuters) - The ransomware attack on

UnitedHealth ( UNH ) that has disrupted payments to U.S. doctors and

healthcare facilities nationwide for a month, has taken an

especially harsh toll on the community health centers that serve

more than 30 million poor and uninsured patients.

Many large healthcare centers have been able to resume

receiving payments and making claims after the hack by using

alternative technology, UnitedHealth ( UNH ) says.

But technology roadblocks have prevented many community

health centers from reconnecting, according to interviews with

national and state-based organizations representing them, two

national groups representing Medicaid directors and plans and

five of the affected centers

One Texas-based association said if the situation continues

through the end of this month, some members will not be able to

make payroll.

UnitedHealth's ( UNH ) Change Healthcare technology is used to

verify insurance coverage, file claims and get paid. With

thousands of customers needing to move to a new connection,

UnitedHealth ( UNH ) has provided loans and urged practices to use

workarounds while it tests and resumes a new system in phases

starting this week.

For Tulip Tree Family Health Care, which operates two

locations in southern Indiana and serves 4,000 rural patients

from Indiana and Illinois, the impact has been "drastic," said

Executive Director Kristine Georges.

Tulip Tree has been unable to shift to a different

clearinghouse or access other workarounds recommended by

UnitedHealth ( UNH ), Georges said. Since Feb. 20, claims have been

piling up, amounting to a $300,000 backlog.

Tulip Tree is one of 1,400 community health centers that

receive grants from federal Health Resources and Services

Administration to cover uninsured patients. Most rely on

payments from the U.S. Medicaid program for low income

individuals and families.

Members of its 32-person staff are submitting claims on

paper or individual insurers' websites, a time-consuming process

that has racked up $12,000 in overtime costs in the past two

weeks.

Even the extra postage is a drain, she said. "There's no fat

to cut."

UnitedHealth ( UNH ) has acknowledged that some providers may need

more restoration work before they can submit claims and that not

all have been able to implement workaround solutions

The company is working with several thousand providers to

help with cash flow issues, including large and small regional

health systems and small, rural independent physician practices,

a spokesman said.

He did not say when claims processing to community health

centers would be restored.

'THE MOST VULNERABLE'

Dr. Julia Skapik of the National Association of Community

Health Centers said centers receive half their revenue from

Medicaid, about 10% from the Medicare program for people aged 65

and older and the disabled, and the rest from private insurers

and grants to help uninsured people.

After several weeks, affected centers are exhausting their

reserves, she said.

Some groups, unable to access the new system, are

waiting for a legacy system to be restored. Others have systems

that are incompatible with proposed fixes, and several are

worried about denials and whether they will soon, or ever, get

paid for these claims, she said.

The U.S. Department of Health and Human Services (HHS) has

instructed Medicaid programs to advance payments to affected

providers.

"We have made clear to UnitedHealth Group ( UNH ) our expectation

that no provider be left behind," an HHS spokesperson said.

John Baackes, chief executive of L.A. Care Health Plan,

which serves low-income communities in Los Angeles County, said

they are making cash advances to small community-based

providers, who "do not have the sophistication or staffing to

turn their claims submission operation quickly."

Isaiah Nathaniel, chief information officer at Delaware

Valley Community Health, which has nine locations in the greater

Philadelphia area serving 50,000 patients per year, said his

organization took a double hit.

While they have taken advantage of some financial assistance

from UnitedHealth ( UNH ), there is still a major shortfall because they

are unable to get reimbursed from some of their largest payers,

one of which asked them to submit paper claims.

They also are unable to connect to UnitedHealth's ( UNH ) new system

because they do not yet have guarantees that the system is

secure. Connecting without that assurance could put their

cybersecurity insurance at risk.

On top of that, Delaware Valley uses Change's call centers

to handle appointments and prescription refills at four centers.

Those are still down with no timeline for restoration.

Lori Hooks of the Texas Association of Community Health

Centers said some centers are seeing just 30% to 50% of their

claims processed, and for a handful, none are going through.

Her association surveyed members last week who said if the

situation persists through the end of March, it may be tough to

pay bills or employees.

"These are clinics that don't have a lot of days cash on

hand and so they're the most vulnerable for not being able to

make their regular monthly bills and payroll," she said.