Form 1099r G distribution

I worked for the federal govt for 27 years. Was on FERS . Retired early last year.  I just received a Form 1099-R 

noting a gross distribution from TSP noting a DISTRIBUTION CODE G . I do now receive a monthly pension 

which I have recorded. However, I never personally received a gross distribution as noted on the TSP  form. 

Was this distribution sent elsewhere? Do I have to report it(it appears so)? Thanks