According to this thread [1], it was the 1978 code that required a dedicated grounding electrode. That's 40 years ago, but of course many houses have not been

According to this thread [1], it was the 1978 code that required a dedicated grounding electrode. That's 40 years ago, but of course many houses have not been upgraded since then, and some localities might not have adopted the 1978 NEC until later. [1] https://forums.mikeholt.com/forum/active-forums/nec/86062-code-year-for-ground-rods?t=135832 https://forums.mikeholt.com/forum/active-forums/nec/86062-co...