Don't have husband sen Don't have husband SSN been separated for many years

Assuming you don’t qualify to file as Head of Household you would file as married separately. Use a made up social security number for your husband to satisfy the program. Then print your return and white out the fake social security number. Mail the return with an explanation. 

it's not clear exactly what you mean by "separated." If you have been living apart but are still legally married, do what Bsch4477 said above.

On the other hand, if you are "legally separated under a divorce or separate maintenance decree," then you are considered unmarried for tax purposes. In that case you should file as single (or head of household if you qualify) and you would not need your husband's SSN. When TurboTax asks your marital status you can select "legally separated."

If you have been separated "for many years," how have you filed your tax return in previous years?