Virgin Mobile locked phone to Sprint 1 year free

Got a question, wondering if someone could answer.
Virgin mobile prepaid phone... can this be swapped in to use on Sprint post paid? I would assume it's locked to VM prepaid only.

starting to read this thread on reddit to find answer.

Is it an iPhone?

You can check the MEID here:

Virgin, Boost, and Sprint Prepaid phones can never be used on Sprint Postpaid, barring a database glitch that might make them eligible-- even after 12 paid months on the prepaid carrier. (Hmmm, I don't know if that applies to Virgin iPhones, though.)

I think there were reports of some of the Boost Moto E5/E6 series clearing for Sprint Postpaid & Sprint MVNOs, but it did not seem to be universal even for those models. There were some threads on Howard Forums & Slickdeals about it, when Boost had significant online markdowns on those models a while back. I bought an E5 Play, and it did clear the CDMA check on Ting/Tello, but returned as ineligible for the Sprint Unlimited deal, and failed the Verizon check. It did check as good for GSM on Ting, but this may well be a false positive-- I didn't try a GSM SIM..

interesting discovery... when checking Sprint iPhones on Ting, you can tell if the phone has been DSU'd or not... if not, shows CDMA.... if DSU'd, shows GSM and CDMA.

Are you sure? In my experience (not recently), if the device MEID is active on Sprint or MVNO, it will show compatibility for CDMA only. If inactive, it will show both CDMA/GSM, if the device supports GSM networks, even if the device is not unlocked.

I used a Galaxy s3 used and bought from vm. On r+. Then cellnuvo

Hm... I think you're right, this seems to match where the phones are being used (iPhones on Mint shows GSM+CDMA and iPhone on Sprint shows CDMA).