This has always been available from the US East Coast, however as far as I've been able to find it doesn't apply to any of LH's gateways east of IAD if I recall correctly. It's a fabulous deal and I used it last year myself. LH's seat is disappointing compared to other more modern F seats, but the service, food, and FCL in FRA are all great. If you are using Business class, the same deal is available on LH, LX, and OS as well (for biz class rates).
(Maybe I stand corrected, seems someone above found SFO-FRA-HND. I've tried several times to get ORD or DTW but it's refused to give me the routing.)