Wall St. Journal:  “Individual retirement accounts funded with 401(k) assets count among your traditional IRA assets during a Roth IRA conversion.  The language is confusing, since many custodians refer to such accounts as rollover IRAs.  But they are technically traditional IRAs. Any IRA labeled as a SEP, SIMPLE or contributory is included, as well. . . . Here is where the ‘back-door’ method comes into play:”