Apparently not according to Hot Air's post about this. See Say, doesnt the Constitution require tax bills to originate in the House?
SNIP..."The bill that passed the Senate wasnt technically a Senate bill. Reid took a bill that had already passed the House, stripped out the provisions to turn it into a shell bill, and then inserted the text of ObamaCare to get around this requirement. The bill that passed the Senate was H.R.3590, which initially had to do with tax breaks for military homeowners. And yes, theyve used the shell bill strategy before. In fact, the conservative opinion today specifically mentioned Article I, section 7 at one point while raising no objection to Reids sleight of hand.."
SNIP...The silver lining here procedurally is that, now that the mandates officially a tax, it falls squarely within the parameters of budgetary matters than can be dealt with in the Senate via reconciliation. That means the GOP will only need 51 votes to get rid of it, not 60.