How to elect OUT of installment treatment on capital gains on sale of rental property

[Coleen3]

Unfortunately, the depreciation is allowed or allowable. You have to recapture it whether you took it or not.
Depreciation allowed or allowable. The greater of the depreciation allowed or allowable is generally the amount to use in figuring the part of gain to report as ordinary income. However, if in prior years, you have consistently taken proper deductions under one method, the amount allowed for your prior years will not be increased even though a greater amount would have been allowed under another proper method. If you did not take any deduction at all for depreciation, your adjustments to basis for depreciation allowable are figured by using the straight line method.
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[ikenacornett]

So will turbotax see the zero and calculate my straight line depreciation for me?

[Coleen3]

No. You have to do it manually and enter it. 3.636% for every full year. First and last years are prorated.