Originally Posted by
invisible
The six month figure comes into light because after that time in a calendar year you are considered to be a tax resident in Singapore. Which you can't be unless you have one of long term visas - WP/EP/LTSV.
Frequent visa runs might become a problem. You need to have a contingency plan what to do if one on such return back you won't be granted entry.
Many people, including the OP I suspect, would want to avoid being denied entry, not just have a contingency plan for if/when it occurs. I would expect Singapore to strictly enforce their laws about this.
Countries, including in Asia, increasingly are suspicious of someone who basically stays there but exits and re-enters every few months to avoid having a continuous stay that exceeds the visa-free period.
OT but IIRC a USA citizen can stay without a visa (assuming that a work permit etc. isn't required) in the schengen area of Europe for a total of three months (or 90 days) in any six month (or 180 days--I'm not sure about the precise details) period, continually re-calculated on a day to day basis.
I asked about lodging plans because it might suggest intent if one were to try to rent a serviced apartment for more than three months and it could be difficult to get a lease if they think that a visa is required.