Traditional 401(k)	Safe Harbor 401(k)
Who May Establish?	Any employer except government entities	Any employer except government entities
Maximum Employee Eligibility Requirements	One year of service, age 21, 1,000 hours; may exclude union employees covered by a collective bargaining agreement.	One year of service, age 21, 1,000 hours; may exclude union employees covered by a collective bargaining agreement.
Employee Deferrals	Up to $23,500 per year. May be reduced by ADP test or percentage limit.	Up to $23,500 per year
Catch-Up Contribution	Age 50-59 and 64+: $7,500 Age 60-63: $11,250	Same as Traditional 401(k)
Employer Contributions	Optional (unless Top Heavy) matching, qualified matching, qualified non-elective and/or profit sharing contribution; total tax-deductible employer contribution limited to 25% of eligible compensation.	Required. Each year, must select either: 1) 3% of compensation to all eligible employees (also satisfies Top Heavy) -OR- 2) 100% match on the first 3% of salary deferred and 50% match on the next 2% of salary deferred (potential total outlay of 4%). Additional optional matching and/or profit sharing contributions; total tax-deductible employer contribution limited to 25% of eligible compensation.
Maximum Allocation	Combined employer/employee contributions for those who are under age 50 cannot exceed $70,000. Participants who turn age 50-59 or 64+ in the current year cannot exceed $77,500. Participants who turn age 60-63 in the current year cannot exceed $81,250.	Same as Traditional 401(k)
Vesting	Employee deferrals, qualified matching and qualified non-elective are 100% immediate; profit sharing contributions up to a six-year graded vesting period; matching contributions up to a six-year graded vesting period.	Employee deferrals and employer Safe Harbor contributions are 100% immediate; profit sharing contributions up to a six-year graded vesting period; non-Safe Harbor matching contributions up to a six-year graded vesting period.
Loans	Permitted.	Permitted.
Withdrawals/Penalty	Withdrawals restricted, but may be allowed due to death, disability, termination of service, hardship, or in-service withdrawal; 10% penalty may apply prior to age 59½ or age 55 if separated from service and taking withdrawals from the plan.	Withdrawals restricted, but may be allowed due to death, disability,  termination of service, hardship, or in-service withdrawal; 10% penalty may apply prior to age 59½ or age 55 if separated from service and taking withdrawals from the plan.
Average Deferral Percentage (ADP) Test	Annual testing requirement which limits the average deferral contribution of the HCEs† to the greater of 1) 1.25 times the average deferral of Non-HCEs or 2) Plus 2% of average deferral of Non-HCEs.	Automatically satisfied.
Top Heavy Test	Annual testing requirement to determine if > 60% of plan assets are in the accounts of Key†† Employees. If so, generally requires a 3% employer contribution to all eligible employees.	Automatically satisfied with 3% qualified non-elective or 3% qualified match to all eligible employees.

^† Highly Compensated Employees (HCE) include: 1) a 5% owner of the employer, or 2) an employee earning > $160,000 in the prior year (and, if employer elects, in the top 20% of employees as ranked by pay).

^†† Key Employees include 1) a 5% owner of the employer, 2) a 1% owner having annual compensation >$150,000, or 3) an officer with compensation > $230,000.