The practical answer
Review line 16 month by month using employment, enrollment, limited non-assessment period, and applicable safe-harbor facts. Apply the official ordering rules when more than one code appears relevant, and leave the field blank when no code applies.
Line 16 is not a free-form explanation of why an employee did or did not take insurance. It uses defined codes whose conditions and ordering matter. A useful review worksheet records the facts and the rule selected, including why an apparent alternative was not used.
This guide uses the final 2025 line 16 instructions. The selected scenarios are deliberately limited. They do not replace the full code descriptions, the employer's chosen measurement method, or arrangement-specific review.
Assemble the facts for the employee-month
Collect employment start and end dates, the full-time determination supporting the month, enrollment start and end dates, and any reviewed limited non-assessment period. Add the employer's documented safe-harbor analysis when relevant.
Record the source for each fact rather than starting from the code used by a prior preparer. An enrollment flag without dates may not establish coverage for the entire month. A current “part-time” label may not establish the relevant ACA status for an earlier month.
Keep unresolved facts visible. If two systems disagree about a termination date, the code reviewer needs that conflict resolved before selecting a monthly result. The worksheet should identify both candidate values and the owner responsible for confirming the actual event.
Use selected code checks as questions
The following are selected checks from the 2025 instructions, not a complete decision tree.
| Question | Code or review path | Important limitation |
|---|---|---|
| Was the person not employed on any day of the month? | Review 2A | Do not use it for a month containing an employment day |
| Was the employee enrolled for every day of the month? | Review 2C | Apply the specific exceptions and ordering rules |
| Does a reviewed limited non-assessment period apply? | Review 2D | Check competing multiemployer treatment |
| Does multiemployer interim relief apply? | Review 2E | Use the applicable-year arrangement guidance |
| Is an affordability safe harbor supported? | Review 2F, 2G, or 2H | Confirm method, eligibility, and ordering |
Record the full applicable definition with the decision. A shortened label in a spreadsheet should not become the only basis for code selection.
Apply ordering and distinguish intentional blanks
Only one Series 2 code is entered for a month. Where multiple facts appear relevant, apply the ordering and exceptions in the instructions. For example, the general enrollment treatment has exceptions for specified arrangements and post-employment coverage. Do not create your own hierarchy by sorting the codes numerically.
A waived offer has no dedicated line 16 code. The IRS employer reporting Q&A explains that declining coverage does not itself establish a reporting exception. Assess the other supported facts for that month.
When no code applies, a blank can be correct. Distinguish that reviewed blank from an unfinished review. Filling every blank with a safe-harbor code can hide unsupported treatment rather than improve completeness.
Fictional example: the termination month differs from later months
Fictional West Linden Company employs Alex as a full-time employee through May 17. Alex's offer and coverage end that day solely because employment ends; they otherwise would have continued. The reviewer confirms the circumstances fit the 2025 termination-month rule described under code 2B.
For this fictional case, May is reviewed under that 2B rule, while June through December are months with no employment and are reviewed under 2A. May is not a 2A month because Alex was employed during it. If Alex later enrolls in COBRA following termination, the reviewer applies the specific post-employment instructions rather than automatically choosing 2C.
The worksheet keeps the May 17 event and the continuing-month facts separately. The example addresses line 16 only; line 14 and any covered-individual reporting need their own appropriate treatment.
Test the support for a safe-harbor entry
Identify which method the employer used, the applicable year or plan-year inputs, the people covered by the analysis, and the source calculation. A code should point to an actual supported analysis, not simply the method available in a software dropdown.
Check the related employer-level facts and the instruction's restrictions before approving a safe-harbor code. Do not substitute an affordability percentage from a different plan year. Also distinguish employer safe-harbor analysis from an individual's complete premium-tax-credit determination.
Where a calculation or eligibility assumption changes, identify the affected employees and months. Keep the reviewed method consistent with its own rules rather than switching entries solely to eliminate an exception report.
Retain a decision another reviewer can reproduce
For each reviewed month, record the selected code or intentional blank, candidate alternatives, decisive fact, instruction reference, and actual reviewer. Attach evidence for unusual cases and preserve the affected output version.
Review recurring combinations across the batch. A repeated termination-month 2A entry or unexplained safe-harbor value may point to a shared mapping error. Investigate the pattern and repair the source or rule before rechecking the affected population.
Use the downloadable checklist for one employee with a midyear event first. If the worksheet cannot explain the event month, add the missing date or source field before applying the method to the rest of the batch.
A monthly evidence review for line 16
Read the workflow as text
- Confirm employment. Preserve dates and the relevant full-time determination.
- Confirm coverage and periods. Record enrollment and any reviewed special period.
- Apply the code rules. Evaluate conditions, exceptions, and ordering.
- Explain the result. Document one code or a reviewed blank with supporting evidence.
Put this guide to work
Line 16 monthly decision checklist
Save the editable text worksheet and use it with your own records. Keep completed copies in your secure working files.
Download the worksheet TXTCommon questions
Must every month contain a line 16 code?
No. A month can be intentionally blank when no code applies. Record that review outcome separately from missing work.
Is there a code for an employee who waived coverage?
There is no dedicated waiver code. Review the actual offer, employment, enrollment, and other applicable facts under the instructions.
Can 2A be used in the month employment ends?
Not if the person was employed on any day of that month. Review the termination-month facts and applicable alternatives.
Does enrollment always mean 2C?
No. The instructions include date conditions, ordering rules, and exceptions. Review the actual arrangement and the whole month.
Can we pick whichever safe harbor produces a code?
Use the employer's supported method and satisfy its conditions. A code is the result of the review, not a substitute for the underlying calculation.
Official sources and scope
Sources checked September 5, 2026. Use the edition for the tax year and filing method you are working with; later instructions may change thresholds, fields, or procedures.
- IRS 2025 Instructions for Forms 1094-C and 1095-C
Line 16 definitions, ordering, termination-month treatment, and safe-harbor restrictions.
- IRS employer reporting Q&A
No dedicated waiver code and intentional blank treatment.