The ABC is bracing for a $20 million a year budget cut the broadcaster says would put the jobs of investigative journalists and reporters in regional areas at risk.

Funding, equivalent to around 10 per cent of the ABC's news budget, will expire this year unless the Turnbull government provides extra money in the May budget as part of the ABC's triennial funding deal.

The previous Labor government gave the public broadcaster $89.4 million over four years for new reporting initiatives and upgrades to its digital services in its last budget. The money was spent on new investigative journalism positions, a fact check unit, suburban newsrooms and extra money for documentaries.

"The $20m funding the news division receives is a significant amount of its annual budget," the broadcaster said in documents lodged with the Senate.