That depends on the type of the retirement plan and is not an option. In most case the simplified method must be used for qualified plans and the general rule for non-qualified plans but there are exceptions.
See IRS Pub 939
https://www.irs.gov/publications/p939
And 575
https://www.irs.gov/pub/irs-pdf/p575.pdf
For information.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**