Losing Dual Eligibility SEP

I received a referral from a client. His friend is leaving California and is dual eligible with a separate Part D drug plan paid for by Medi-Cal. She is moving to Colorado and will no longer be dual eligible.

I know she has a SEP for a MAPD but another agent told me she also has a SEP for a Medicare Supplement. I can find no mention of SEP at Medicare.gov or at DORA (department of regulatory agencies) for Colorado.

Am I missing something?

Source of insurance-forums.net