[cookiecaper]

Define "enough". $3600/mo is $43.2k/yr, which is a few k/yr less than the nationwide median income. Keep in mind that in many areas, two wage-earners (that is, $100k+/yr) are required to maintain a middle class standard of living.

It could be pretty adequate if the potential retiree has planned well and has already paid off their home (a typical house payment in an area of the country with a sane cost of living would probably be between $1k-$1.5k). It'd really help to have some decently-sized retirement accounts.

Basically, $3600/mo is adequate maintenance money, but add one or two major expenses to that (like a house, car, or major medical bill), and it gets dicier. If you want to travel during your retirement, or do anything besides buy groceries, you'll need significant savings to draw from.

[woofyman]

Plus health insurance costs.

[toomuchtodo]

Medicare + subsidized supplemental insurance from the ACA (due to less income in retirement years).