I turn 69 in Jan 2019 and am applying for SS. When should I have my benefit start so I get my age 69 benefit amount.
You'll get your age 69 benefit rate if you choose to start your retirement benefits effective with January 2019 assuming that you weren't born on January 1st. That would be the payment that Social Security normally makes in February 2019, since they pay benefits in the month after the month that the payment covers. If you were born on January 1st, you'd get your age 69 rate if you file effective with December 2018.
You can file your application up to 4 months in advance of the month you want to claim benefits, so if you've firmly decided on starting to draw at age 69 you could apply at any time now. Before filing, though, you may want to consider using our software to be sure that you're making the best possible choice.