Latest hospital waiting lists for June show that the numbers remain high with an overall increase of about 5,500 cases.
The number waiting for gastrointestinal checks has reduced and there have been falls in other areas too.
There were a total of 677,500 people waiting last month, compared with 672,000 in May.
The figures are published by the National Treatment Purchase Fund.
They show there were 86,018 people waiting for inpatient, or day case treatment.
There were 18,835 waiting for a gastrointestinal check, down from 19,281 in May.
Also, 484,346 patients were waiting to be seen at an outpatient clinic for the first time.
The figures also include over 88,395 patients who have a scheduled procedure within about six weeks, plus those waiting for an annual check.
Private hospitals say they have now begun to receive referrals from public hospitals, under the treatment purchase scheme and have immediately started treating several hundred patients.
Simon Nugent, Chief Executive of the Private Hospitals Association, said this has slowed the growth of public waiting lists.
But he said there was still a mountain to climb with the scale of inpatient lists and the number waiting over 15 months.
