In order to join your family (spouse, registered- and cohabiting partner) or relative in Sweden, you must have a residence permit.
As of 20 July 2016, a temporary act will limit the possibility for close relatives of persons in need of protection with temporary residence permits to immigrate to Sweden. More detailed information about these regulations is available on the Swedish Migration Agency website
Moreover, the general rule is that anyone living in Sweden should be able to support themselves and their family members who may be granted residence permits. The maintenance requirement will not apply, under certain conditions, to those who have been granted residence permits in Sweden as persons in need of protection. One important requirement is that close relatives must apply for residence permits within three months of the date on which the person in need of protection was granted a residence permit.
Other rules apply if you or the close relative in Sweden are citizens of an EU/EEA country (other than Sweden). A close relative may for instance be a husband or wife, a common law spouse or a child (a minor).
The quickest and easiest way to apply for a residence permit is to apply online over the Internet. An online application goes directly to the Swedish Migration Agency and is given priority. The Agency aims to reach a decision within four months.
Swedish Migration Agency web application
If you cannot or do not want to apply online, you can submit an application document in person to the Swedish embassy. You need to make an appointment.
Read about the rules, which documents are required and how to apply step by step on the Swedish Migration Agency website
Moving to someone in Sweden - Swedish Migration Agency (migrationsverket.se)
Application fees for residence permits to live with someone in Sweden - Migrationsverket