Form W-2 is a federal form, not a state form, so the instructions for the federal W-2 is what should be followed. Those instructions state SDI should be in box 14, not 19, whether the state website says box 19 or not. Here are the W-4 instructions from the IRS W2 instructions form and it's on the back of the W-2:
Box 14. Employers may use this box to report information such as state disability insurance taxes withheld, union dues, uniform payments, health insurance premiums deducted, nontaxable income, educational assistance payments, or a member of the clergy’s parsonage allowance and utilities. Railroad employers use this box to report railroad retirement (RRTA) compensation, Tier 1 tax, Tier 2 tax, Medicare tax, and Additional Medicare Tax. Include tips reported by the employee to the employer in railroad retirement (RRTA) compensation.
BTW: opinions on these things should always be backed up with references to credible sources. Even as a CPA, the opinion is not necessarily a credible source. Hope this helps!
