upgrade to TS clearance with an adjudicated past with a secret clearance

I am looking to upgrade my clearance. scouring the internet, it says if you are denied a TS you lose your secret. I have a background that was adjudicated and now due to my skill set my employer wants to upgrade me to TS. I’d like to, but nervous to lose what I have, if something has already been adjudicated and I was granted a Secret would I need to adjudicate it again?

The short answer is yes, it would be need to be adjudicated again.

But fear not, the adjudication criteria is the same for all clearance levels (Confidential, Secret, Top Secret). That is, something that would be grounds for a denial for Top Secret would also get you denied for Confidential or Secret.

The only difference is the scope of the investigation. For Tier 3 investigations (Secret), they go back 7 years. For Tier 5 (Top Secret), they go back 10 years.