My return shows zero AGI and taxable income, even though I have Social Security benefit amount in 5a, but taxable amount in 5b shows Zero. Is that correct b4 I file?

[DoninGA]

If you have no other income reported on the tax return or just a minimal amount of other income, that would be correct, none of your SS benefits are taxable.

Up to 85% of Social Security Retirement/Disability/Survivors benefits becomes taxable when all your other income plus 1/2 your social security reaches:

Married Filing Jointly - $32,000
Single or Head of Household - $25,000
Married Filing Separately - 0

If the Social Security benefits are the Only income to be reported on the tax return, then there is no reason or need to file a tax return.

A tax return with no taxable income being reported cannot be e-filed.