If I sell my primary residence and put all the proceeds into buying a new primary residence (in California) am I liable for capital gains tax ?

[xmasbaby0]

The last time it mattered whether you used the gain from the sale of a house toward the purchase of another house was in 1997.   

SALE OF HOUSE

If your gain was more than  $250,000 filing Single, or more than $500,000 filing Married Filing Jointly the sale must be reported on your tax return.  Whether you re-invested the gain in to another house is irrelevant.  If you  have a Form 1099-S go to Federal>Wages and Income>Less Common Income>Sale of Home (gain or loss)

If you owned and lived in the home as your primary residence for at least 2 of the last 5 years on the date of the sale, you do not have to report the home sale if the gain is less than $250K filing Single, or less than $500K filing Married Filing Jointly (and you both owned and lived in the home for at least 2 years).

• If you are using online TT, you need Premier or Self-Employed software to report the 1099-S

[NCperson]

@robingadams - what you do with the proceeds has no bearing on the capital gain.  That used to be the case, but went 'out the window' in 1997.

Your capital gain is 

1) the selling price of the house LESS

2) the improvement made while you owned the home LESS

3) the purchase price of the house year ago LESS

4) the selling costs, the biggest one is normally the commission.

THAT is your profit on the house and is subject to capital gains tax.  However, for the federal return, as long as you have lived in the home for 2 of the past 5 years, you can reduce that profit for tax purposes by $250,000 (filing single) or $500,000 (filing joint),  What remains is then subject to capital gains tax. 

State tax may work differently,