Anyone who is identified as a close contact of someone who has tested positive for coronavirus in Scotland will be asked to get a test.
The measure, which comes into force tomorrow (Thursday) is designed to find asymptomatic cases that would otherwise go undetected.
Previously, outbreak incident management teams have had the ability to order testing of close contacts on a case-by-case basis, in line with local assessment of clinical risk.
Now everyone who has been identified as a close contact via the Protect Scotland app, or through manual contact tracing, will be provided with instructions on how to book a PCR test.
The Scottish Government says the approach does not replace the need for self-isolation - and anyone who tests negative will still have to quarantine for 10 days.
Those who test positive will be asked to self-isolate for a further 10 days from the time of their test result, to ensure they are no longer infectious when they leave self-isolation.
Public Health Minister Mairi Gougeon said: "Testing close contacts is a significant step in enhancing our public health response, as it will enable us to find asymptomatic cases that would otherwise go undetected, helping us to stop the spread of this virus through our communities.
"This is especially important given new Covid strains are more infectious, and not everyone who has coronavirus will have symptoms, so people could be spreading the disease to those around them without knowing it.
"This expansion is possible because of increases in our testing capacity, delivered through our new regional hub laboratories, which will help us suppress Covid to the lowest level in Scotland.
"However, it’s important to remember the incubation period of Covid means that a person could still test positive at a later stage in their isolation period - so a negative test does not mean you should stop self-isolating, and everyone should continue to follow the restrictions that are currently in place."