The figures released on Tuesday in response to Senate estimates questions have punctured the Turnbull government's claim that bulk-billing was at a record high despite its rebate freeze, the Royal Australian College of GPs says.

The department warned that quoting the two-thirds figure as the national bulk-billing rate was misleading.

About 64.7 per cent of patients had all their GP visits bulk-billed over the past financial year, leaving roughly one-third out of pocket for at least one visit to their GP, the Department of Health disclosed on Tuesday in response to Senate estimates questions.

The headline 2015-2016 bulk-billing rate was 85.1 per cent, the department told Senate estimates in its answer to a question on notice.

"On an average weekday, some 450,000 to 500,000 patients visit a GP and 85.1 per cent of those people are bulk-billed," a spokesperson from the department said in a statement.

The Turnbull government has consistently cited the figures over 80 per cent as proof the GP rebate freeze had not driven people away from accessing primary health care.

But RACGP president Bastian Seidel seized on the 64.7 per cent figure, saying it vindicated the college's claims that the bulk-billing rate had become a casualty of political spin.

An RACGP report released in September suggested 69 per cent of GP consultations were bulk-billed, and patients were paying an average of $48.69 in out-of-pocket fees.

Dr Seidel said the conversation needed to move away from using the bulk-billing rate as a benchmark.

"We should be looking at how much patients pay in out-of-pocket costs.

"Medicare rates haven't kept up with the rising costs of health care. That's the bottom line," Dr Seidel said.

"We know that financially vulnerable patients will delay seeing their GP if they are faced with increased out-of-pocket expenses, and they will eventually call an ambulance or present to emergency departments at a much greater cost to the taxpayer," he said.

About 81 per cent of patients had at least half of their GP visits bulk-billed, and 89 per cent bulk-billed at least one GP visit over the same period, according to the department.

A spokesperson for the department said the proportion of people who paid no out-of-pocket costs for any GP visit had increased from just over half in the last decade

"Similarly, the proportion of patients who were never bulk-billed has halved over the same period, from 22.7 per cent of patients in 2004-2005 to 10.8 per cent of patients in 2015-2016.

"None of these figures represents the official bulk-billing rate, and none of them can lay any greater claim to represent the average patient experience of visiting a GP," the spokesperson said.