Are H1 approvval and COS approval different things?

[ganeshkudale]

Is COS(change of status) a different procedure than H1 approval?
Do we have file cos saperately and get approved?
I already have L1 till dec, and h1 approved 2.5 months prior. Can I choose when to file COS?

[kabkaba]

Read the H1 approval notice, does it state that change of status has been approved? Does it have an I-94 at the bottom? If you don't have the approval notice, ask this question to your H1 employer.