You can get accurate results using a gross benefit estimate or a gross current benefit amount in some cases while in other cases doing so will cause inaccurate results.
You can get accurate results using a current benefit amount or an age 70 benefit estimate if the individual has no current or future covered earnings, i.e., earnings taxed by the Social Security Administration (SSA).
When there are current or future covered earnings, to calculate accurate results the software needs the full earnings history so it can determine whether any of the current or future earnings will replace lower earning computation years. Computation years are the 35 highest earning years of income after indexing for inflation. Social Security uses them to calculate a person's primary insurance amount (PIA), which determines how all the benefits drawn on that person's record are calculated.
If there actually are no current or future earnings, remove all earnings prior to the current year and set the Last Year with Earnings (Maximize My Social Security) or Retirement Age (MaxiFi) to the past year when earnings stopped.
When you use an age 70 benefit estimate, the software accounts for the fact that Social Security purposefully lowballs benefit estimates by unrealistically assuming zero future wage growth and zero future inflation, counter to all our post-war history.
When you can't get accurate results using benefit amounts or Social Security's estimates, you can enter the earnings history manually or import them using the XML file option (Import Your Social Security earnings: XML) or the copy and paste option (Import Social Security Earnings: Copy and Paste).