Are there individual (not Group) health insurance policies that focus on covering outpatient medical costs such as for specialist/GP visits? Can such policies be added as a rider to shield policies?

Hi there, yes there is. They are the international health plans. but you can limit your coverage to singapore only, thereby reducing the premium slightly...

Depending on your age it can cost from $150-$300 per month.

Thus not many people purchase such plans.

From what I know, there isn't such a rider yet in most of the shield plans in singapore.

However one hack would be.. if you are a NSmen or able to be covered under the Aviva x Mindef Scheme. There's that option for you to be covered for outpatient as MINDEF would be your employer, and thus you are under the group outpatient medical. Do check out their website for specific requirements.