I applied for Social Security on June 1, 2024 in advance of turning 70 later this year. If I recall correctly the website said it would take 30 days for a decision. However I didn't hear anything until yesterday, August 31. I received an email saying a decision had been made and upon logging into their website found out that my application had been approved. This was expected as my case was pretty straightforward having worked for two big employers a combined 40 years. Nevertheless it took them three months to approve the application. This made no difference to me as I had applied as early as possible (four months in advance) and am not due my first check until November. And I have no urgent need for the money. However if you do need the money or your application is at all complicated it would probably be a good idea to apply as early as you can.
The amount of your Social Security monthly benefit depends in part on when you start taking it. You receive the smallest benefit if you start taking it as soon as you are eligible which is when you are 62. Past age 62 each month you delay taking it increases the amount until you reach age 70. Further delay past age 70 is pointless as your benefit stops increasing. I have read (but not verified) that taking the benefit early or late makes little difference from an actuarial stand point. Based on this, I decided to take it as late as possible as that would give me the biggest benefit if I lived a long time and might need it. Also I tend to procrastinate.
My full retirement age is 66. According to Social Security this means that starting your benefit four years early at age 62 costs you 25% compared to starting it at age 66. Whereas waiting until age 70 increases your benefit by 8% a year or 32%. In practice it is more complicated as there are various inflation adjustments made each year. In my case I had maximum earnings each year. Social Security has computed a table giving the initial and current monthly benefit based on your age and year you retired for maximum earners like me. If I had started taking the benefit at my full retirement age in 2020 I would now be getting $3623 a month. But by delaying until this year I will getting $4873 a month. Which is 34.5% more.