Victoria posted Australia's worst ambulance call response times last financial year but there are signs the embattled system is beginning to rebound.

The Productivity Commission released the health component of its 2023 government services report on Thursday, highlighting the state of Australia's ambulance services.

It showed the proportion of triple zero calls for an ambulance answered by an operator within 10 seconds or less plunged to 81.3 per cent in 2021/22, down from 89.2 per cent the previous financial year.

Victoria fared the worst of all states and territories, with about two in three calls (65.6 per cent) answered within 10 seconds, down from 88.9 per cent in 2020/21.

Results deteriorated across every jurisdiction except Western Australia but only Victoria fell below the 85 per cent mark.

Victoria's triple zero call-taking service, the Emergency Services Telecommunications Authority (ESTA), was thrown into disarray after COVID-19 restrictions were relaxed in October 2021.

Response times in the state hit record lows during the first Omicron wave in January 2022 and a report linked 33 deaths to call delays.

The Victorian government has since committed to overhauling the service and allocated $333 million to recruit and train almost 400 extra call-takers.

A Victorian government spokesman said ESTA had met or beaten its monthly call-taking target to answer 90 per cent of emergency ambulance calls in five seconds or less each year since 2015 before the surges during the pandemic.

Call-taking performance has improved since January 2022 and the government is claiming credit for providing "substantial funding" to the service before and during the pandemic.

"Almost 99 per cent of calls in January were answered within five seconds - a record," the spokesman said.

"ESTA advises it has met and exceeded the benchmark of 90 per cent of calls answered in five seconds every month since August."

But opposition health spokeswoman Georgie Crozier said the government invested in the state's triple zero system far too late after multiple warnings.

"Sadly, for too many Victorians and their families, they've paid a very big and sad price," she said.

Victorian Ambulance Union general secretary Danny Hill said every state and territory needed more call-takers to cope with soaring demand but the figures showed the problem was more pronounced in Victoria.

"More could have been done," he told AAP.

"We saw specific performance issues with Victoria down to the fact they just didn't have enough staff.

"Government did recruit quickly once the issue became quite known and returned the service to where it should have been. But it should never happen."

The Productivity Commission report shows there were 4.2 million incidents reported to ambulance services across the nation last financial year and 5.3 million responses where an ambulance was dispatched.

There can be multiple responses to an incident.

State and territory-wide ambulance response times were longest in South Australia (58.3 minutes), NSW (36.8 minutes) and Tasmania (34 minutes), although data from SA cannot be compared because of technical reasons.

TRIPLE ZERO CALL ANSWER TIMES BY JURISDICTION FROM 2020/21 TO 2021/22

(Proportion of ambulance calls answered by call-takers in 10 seconds or less)

* NSW - 94.1 per cent to 86.7 per cent

* Victoria - 88.9 per cent to 65.6 per cent

* Queensland - 89.1 to 85.8 per cent

* WA - 83.8 per cent to 86.5 per cent

* SA - 95.4 per cent to 92.9 per cent

* Tasmania - 95.2 per cent to 92 per cent

* ACT - 95.2 per cent to 95.1 per cent

* NT - 89.2 per cent to 87.1 per cent

SOURCE: The Productivity Commission