All state schools in Wales will reopen to all pupils in September for the first time since the coronavirus lockdown started in late March.
Education Minister Kirsty Williams has said children will not have to socially distance with those in their class or “contact group” of about 30 pupils.
Adults in schools, however, will have to socially distance with each other.
The minister added that parents and carers would not face a fine for not sending their child to school in Wales.
The news comes as 900 extra teaching posts are to be created in Wales to help pupils catch up when they return.
Detailed guidance on how children will return to school in Wales will be published next week when most of Wales’ school pupils will be in their final week of a shortened summer term.
“Schools will return to full capacity with only limited social distancing within contact groups,” said Ms Williams.
“At full operations, a contact group should consist of around 30 children. Some direct or indirect mixing between children in different contact groups will also be unavoidable.
“Schools will be required to minimise the risk of transmission by taking other mitigating measures. Social distancing for adults should remain in line with the regulations and guidance.”
Ms Williams said all pupils should return “if possible” from 1 September – the first day of the new term – but schools can have “two weeks flexibility” if headteachers want to prioritise the return of some year groups.
The minister wants all pupils “accommodated” by Monday, 14 September.
But Ms Williams said “lingering concerns” among parents and carers meant there would be no fines for not sending children to school.
“We want all children to be back in September, but I recognise that there may still be lingering concerns,” she told the Welsh Government daily briefing.
“So initially we will not to be imposing fines on parents who choose not to send their children back.
“But we will be expecting schools to reach out to those parents, to do that now… to discuss with parents now any concerns that they may have.”
Ms Williams said the Welsh Government’s no-fining policy for parents would be “kept under review”.
“At some stage we may indeed return to the situation as it was pre-Covid, where fines will be issued to parents,” she added.
There has been growing pressure on the Welsh Government to spell out plans for September with most schools closing for the summer in just over a week.
Getting everything in place to welcome all pupils back next term will be a challenge and detailed guidance from the government won’t be published until next week.
A full return seemed inevitable after all other parts of the UK said that was their aim.
But there are plenty of practicalities to sort out, including school transport.
And any spike in the virus over the summer holiday could derail the plans in some areas.
All schools that can accommodate all pupils from the start of the term should do so.
There will be a period of flexibility in recognition that schools may want to focus on priority year groups, such as those new to secondary schools, those sitting exams next summer or those in reception classes.
This already happens in many schools, and we have been learning from practice elsewhere. It will also allow time, up to a fortnight, for any planning and reorganisation.
The UK Education Secretary Gavin Williamson announced in June that all pupils in all year groups in England would go back to school full-time in September.
There had been growing pressure on the Welsh Government to set out its plan for how schools might reopen in September as a petition with more than 9,000 signatures has been created calling for pupils to return full time after the summer.
Announcing the September return, Ms Williams said maintaining “contact groups” may be difficult in certain circumstances, like on school transport, but controls would be in place.
The announcement comes two weeks after schools in Wales reopened on 29 June – and on the day of the Welsh Government’s pledge to create an extra 900 teaching posts.