Alcohol will remain on sale to people aged 18 and 19 after a conscience vote in Parliament.
MPs held a heated debate on Thursday afternoon about whether to keep the status quo, raise the purchase age to 20, or split the age so 18 and 19-year-olds could buy liquor at pubs, but not from shops.
The MP behind the amendment to the Alcohol Reform Bill to raise the drinking age back to 20 is National's Tim Macindoe, who told Parliament youth drinking is a profoundly important issue.
"And to those who say we're singling out young people and piling all the blame on them, I say that is absolutely untrue.
"We are looking at protecting them from an aspect of their lifestyle - our whole lifestyle - that is doing enormous damage."
But National Party colleague Tau Henare did not agree, saying young people are not the biggest problem drinkers.
"We expect young people if they want to, to join the Army and go across the world and defend whatever we say. And we expect them to do a whole lot of things at 18 - but they can't have a beer? Give me a break."
Following the debate, the first round of voting resulted in the split age option being dropped, as it got the least support with 33 votes. In this option, 18-year-olds would be permitted to buy alcohol in a pub, club or restaurant, and an age limit of 20 would apply to alcohol purchased at a shop.
The final vote resulted in 68 MPs voting to keep the purchase age at 18, and 53 voting to raise the age to 20.
But a mistake in the counting of the individual conscience votes means the majority was incorrectly recorded as 69 in favour and will be corrected when Parliament next sits on 11 September.
It is the second conscience vote in the House this week, which allows MPs not to adhere to party lines.
On Wednesday, the Marriage (Definition of Marriage) Amendment Bill, which would make same-sex marriage legal, was passed by 80 votes to 40.