Social Security is in edicts...

Thanks a lot

Running the Social Security edict is usually the best option once it becomes available, but you can also:
- Build certain lower-end housing options (Bunkhouses and Conventillos in the base game, Capsule Home Clusters with New Frontiers, Residential Boats with Tropican Shores) that have work modes which make the housing available to Broke Tropicans.
- Run the Free Housing edict, which makes all housing available to all Tropicans regardless of wealth level but also removes all income from housing.
- Set the constitutional labor policy option to "A Life's Work," which will cause retirees to take jobs as long as jobs are available, thus making them at least Poor.
- Set the constitutional marriage rights option to "Forced Marriage," which will often though not always result in retirees having working-age spouses, thus making them at least Poor as long as the spouse is employed.

Note that most services also have wealth requirements, so if you aren't doing something to ensure that your retirees are at least Poor then you may want to consider how to provide services for them. Tropicans can get free food from food-producing buildings as long as you aren't running the "No Free Lunch" edict and have not disallowed local consumption at the building (Fishing Wharves provide a marginally-higher service quality than other food-producing buildings), free healthcare from Chapels on "Help First, Preach Later" or from actual healthcare facilities if the constitution healthcare option is set to either "Single Payer System" or "Hybrid System," and free entertainment from Buskers, Botanical Gardens (unless set to the "Private Garden" work mode), and maybe one or two other buildings.

Thanks a lot, I used to Social Security and it taking care of the homeless problem nicely

Yup. Thats why social security was implemented in the US, to help reduce elder poverty and homelessness.