Steve J
The TSP Guide that DBA referenced is a good resource. With the subscription you can call or email the author with questions.
It isn't really that difficult. If you are over 55 and under 59.5, TSP is the better option for withdrawals for simplicity, flexibility and avoiding any penalties. Under IRA you can also make withdrawals but to avoid penalty, you have to meet one of the exceptions--primarily 72t or Substantially Equal Periodic Payment (SEPP). SEPP is the same as Life Expectancy Payments prior to age 70.5 TSP uses this in second column when you use
https://www.tsp.gov/PlanningTools/Calculators/retirementCalculator.html. Withdrawing from TSP will simplify any tax implications as your 1099R will be coded correctly, there is no 10% penalty and you can change the amount you need each year.
Note: All traditional TSP $$$ are taxed as ordinary income. Since you are getting a pension, I would suggest you use actual filing status for withholding plus make additional withholding or estimated tax payments if necessary considering your total estimated income based on your Pension, TSP Withdrawal and any other income.
If you transfer part of your TSP to an IRA the rules in IRS Publication 590-B
https://www.irs.gov/pub/irs-pdf/p590b.pdf apply which would force you to use 72t rules or some other exception in order to access funds without penalty. I assume the financial planner talking about creatively setting up different IRAs would use the same life expectancy calculations to determine how much you would need to put in the IRA you would be withdrawing from based on your needs. The big issue with this is that you will be locked in to this method for 5 years (see
Recapture tax for changes in distribution method under equal payment exception on page 23 of 590-B) based on your age.
If you want to transfer part of your TSP to an IRA for any reason, you need to do the partial withdrawal prior to making the full withdrawal (monthly payments can be any amount you choose >$25/month) based on current rules. I would recommend only transferring money you will not need to withdraw before age 59.5.
One clarification: Is all of your TSP traditional or do you have Roth or any after-tax contributions in your account? I am assuming all is traditional in my response.