Richard gave you good advice...
A few other things to consider. PA needs to do pension reform on SERS and PSERS. Whether there is the political will to do so and what the solution turns out to be, remains to be seen. It almost certainly will include a reduction of future benefits if it happens.
To make TIAA-CREF worthwhile, you need to be heavily vested in equities. If you are risk adverse, this might not be the right path for you.