When did the mint start to include COAs with Mint Proof Sets?

Herb_T

When did the mint start to include COAs with Mint Proof Sets? Anyone know the first year that they started adding the COA?

slimbert

1986 was the first year that proof sets included COAs.

1986 COAs were dated "1986".

1987-1998 used a few different types of generic, non-dated COAs.

Herb_T

@slimbert said:
1986 was the first year that proof sets included COAs.

1986 COAs were dated "1986".

1987-1998 used a few different types of generic, non-dated COAs.

Thank you!