Is it in the United States? If not, 40 years is correct.
Why do you think it is depreciating it over 40.6 years? If this is the first year, it only gets a partial amount of depreciation. Is that what you are confused about? So yes, a 39 year recovery period actually is depreciated on 40 tax returns, because the first and last year only get a partial year. When EXACTLY is the "placed in service" date?
