The Salvation Army and the Public Service Association (PSA) say Budget funding to address issues like the housing crisis and child poverty are good - but not enough.
"It is not the transformational change we had hoped for," Salvation Army Lieutenant Colonel Ian Hutson said.
This Budget will not rid New Zealand of the combined plagues of homelessness and child poverty, he said.
The Salvation Army commended the Government for funding free Health Care for all children under the age of 14 years, increased investment in early childhood education, an expansion of the community card to HNZC and Accommodation Supplement clients, and investment in new approaches to criminal offending, which were "all very welcome initiatives".
"Sixteen hundred new public rental houses is also a welcome commitment by the Government to meeting housing need, but it still falls short of the 2000 public rental houses a year ... required to arrest homelessness."
The 2018 Budget was an important step in the right direction but further investment was needed in critical areas, Hutson said.
Similarly the PSA, the union for public servants, said the Budget showed promise but there were still many in the public and community service wondering when their turn is coming.
"Overall, we are heartened by this Government's approach and the priorities it has signalled for the future," PSA National Secretaries Erin Polaczuk and Glenn Barclay said in a joint statement.
"In particular, we are happy to see money allocated for pay rises for some PSA members who have struggled for too long under a pointless resourcing and salary cap.
"It was good to hear Minister of Finance Grant Robertson specifically mention the need to rebuild public services to the standard that New Zealanders need and deserve."
The PSA welcomed the emphasis on frontline services, including more probation officers and more staff for DoC and Customs.
More probation officers meant prisons would be safer for PSA members who work there, and allow them to carry out crucial rehabilitation work, the pair said.
However, the PSA's position was that the Budget did not specifically address 10 years of pay freezes and generations of gender pay discrimination - both of which have hit PSA members hard.
"This Budget will address some of the areas of biggest need but given the level of forecast surpluses, we would have liked to have seen more.
"Additional funding for health should cover population changes and existing cost pressures, but there is nothing left to expand services into areas of great need - and nothing for pay equity or wage increases for hard-working employees.
"Indeed, we are disappointed to see there is no specific contingency allocation for Equal Pay.
"It remains an 'unquantified risk', when there are specific claims already raised and unions want clarity around whether settlements will be funded.
Given closing the gender pay gap in the core public service was a central commitment for the Government, the PSA had expected to see money dedicated to this.
"We encourage the Government to build on what it's started."