Frequently Asked Questions Regarding the Usage of Person Months
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 Public FAQs NIH Staff FAQs
Usage of Person Months

Initial Posting: April 21, 2006
Last Revised: May 16, 2011

1. What is the definition of person months?
Person months - Is the metric for expressing the effort (amount of time) PI(s), faculty and other senior personnel devote to a specific project. The effort is based on the type of appointment of the individual with the organization; e.g., calendar year (CY), academic year (AY), and/or summer term (SM); and the organization's definition of such. For instance, some institutions define the academic year as a 9-month appointment while others define it as a 10-month appointment.
2. How do you calculate person months?
Conversion of percentage of effort to person months is straight-forward. To calculate person months, multiply the percentage of your effort associated with the project times the number of months of your appointment. For example:

25% of a 9 month academic year appointment equals 2.25 (AY) person months (9 x .25= 2.25)

10% of a 12 month calendar appointment equals 1.2 (CY) person months (12 x .10 = 1.2)

35% of a 3 month summer term appointment equals 1.05 (SM) person months (3 x .35= 1.05)

Another example:

If the regular pay schedule of an institution is a 9 month academic year and the PI will devote 9 months at 30% time/effort and 3 months summer term at 30% time/effort to the project, then 2.7 academic months and .9 summer months should be listed in the academic and summer term blocks of the application (9 x 30% = 2.7 person months; 3 x 30%= .9)

See Percent of Time & Effort to Person Months Calculator (Excel - 20 KB).
3. How will this affect monitoring of percent effort when there is an increase/decrease and when you are determining overlap and over- commitment?
Resolution of overlap normally occurs at the time of award in conjunction with applicant institution officials, the principal investigator, and awarding Institute or Center (IC) staff.

In reviewing person months, IC staff will continue to pay close attention to other support pages and budget justifications (for modular applications) to determine if any personnel exceed 12 person months of funding. Personnel with over 12 person months would be the indicator of over- commitment (i.e. 12 person months translates to 100% effort).
4. How will NIH enforce effort requirements in mechanisms, such as Ks, or in RFAs/PAs where minimum effort is stated?
Enforcement of effort that is required by mechanism (i.e. K awards), can still be upheld using the person month's metric. For instance, K awards require a minimum of 75% of full-time professional effort at the applicant organization, which must be spent conducting research career development and clinical research. This is based on a 12 month calendar year. If an individual has an academic year (AY) appointment, the required 9 person-months devoted to the K may be fulfilled in several ways.  Following are three examples:

A. By devoting 100% effort during 9 academic months of the AY (1.0 x 9 = 9 person-months).

B. By devoting 75% effort during 9 academic months of the AY (0.75 x 9 = 6.75 person-months), AND also devoting 75% effort during 3 summer months (0.75 x 3 = 2.25 person-months).

C. By devoting 67% effort during 9 academic months of the AY (0.67 x 9 = 6 person-months), AND also devoting 100% effort during 3 summer months (1.0 x 3 = 3 person-months).
No matter what calculation is used, when calculating using a metric other than calendar months, any combination of academic and summer effort must still equal the equivalent of 9 calendar months.
5. How will the use of person months affect the request for other support for competing and non-competing grant applications?
NIH uses Just-In-Time procedures for the request of other support. Information on other support assists awarding IC staff in the identification and resolution of potential overlap of support. Overlap is not permitted, whether it is scientific, budgetary, or a commitment of an individual's effort greater than 100 percent.

Effective with PHS 398 applications prepared for submission/receipt dates on/after May 10, 2006, utilizing forms dated “Rev. 4/2006,” , applicants will be required to report effort using the person month metric for the detailed budget (see NOT-OD-06-056). For modular applications, the Personnel Budget Justification instructions have been revised to reflect person months (calendar, academic, and summer) as the measure for effort.

For this same cohort of applications (i.e., those prepared for submission/receipt dates on/after May 10, 2006), when Other Support is eventually requested, it should also reflect person months as the measure of effort.
6. I submitted an application before May 10, 2006 so it used percentages in the budget to measure effort. I'm now being asked to submit Other Support. How should effort be reflected?
Ideally the metric should be consistent. So for any applications submitted before May 10, 2006 that used percentages as the measure of effort, then the Other Support information should also be submitted using percentages.
7. What will be the impact on non-competing grants and the All Personnel Report in the Type 5 Progress Report (SNAP/non-SNAP)?
The format for the All Personnel Report Page has been revised to replace the Percent Effort column with the 3 columns of person months (calendar, academic, and summer). For progress reports submitted for due dates on/after June 1, 2006, grantees will be required to use the new format.
8. What will be the effect on IC prior approval for significant change in Status?
As stated in the NIH Grants Policy Statement (NIH GPS), the grantee is required to notify NIH if the PI or other key personnel named in the NGA will withdraw from the project entirely, will be absent from the project during any continuous period of 3 months or more, or will reduce his/her time devoted to the project by 25% or more from the level that was approved at the time of award. For example, a proposed change from 40 percent effort to 30 percent or less effort is greater than a 25% reduction and would require NIH prior approval). NIH must approve any alternate arrangement, including any replacement PI or other key personnel proposed by the grantee.

Assuming a 12 month calendar year appointment, 40% effort = 4.8 calendar months; 30 % effort = 3.6 calendar months. So the change of 1.2 months or more would constitute a change in status requiring prior approval. (The same calculation can be accomplished by calculating 4.8 calendar months x 25% = 1.2 months.
9. When NIH transitions to person months, in lieu of percent effort, how will NIH translate a minimum required effort into person months?
NIH does not set “minimum effort requirements” for the regular research project grants. The only NIH grants that have a minimum effort requirement are the Career Awards (K's). To translate the minimum effort requirement for K awards (75%) based on a 12 month calendar year appointment the calculation would be 12 x .75= 9 person months.
10. How will the change to person months impact E-SNAP Submissions?
The equivalent of the All Personnel Report in the E-SNAP module of the eRA Commons (e.g., the Edit Business/All Personnel screens) reflects the same 3 columns of person months.
11. Can decimals be used in the All Personnel eSNAP screen?
Yes, up to 1 decimal place can be used (i.e., 1.2 academic months is an acceptable value). Consistent with the instructions for the All Personnel Report (2.2.8 in the PHS 2590), you may enter less than one person month for the PD/PI(s) only.  For all other personnel, only those who participate for one person month or more should be included in the All Personnel Report regardless of senior/key designation.  The person month information provided in the progress report is used by NIH for reporting purposes only; it is not used to monitor effort on an award or for budgetary purposes.
12. On the new paper PHS398 forms that ask for month's effort, should we still enter 1 month (for a .60 month effort) and address this in the budget justification? Or, since the paper form is not controlled electronically, shall we enter "reality" i.e., .60 months?
Based on 12 calendar months with 5% time and effort devoted to the project, the grantee should use the “reality” number of .60 months on the new paper PHS398.
13. How should we list partial months? In the budget period on the SF424 (R&R) application, the number of calendar months that a senior key person worked on a project may be listed as between 1 and 12 months. However, some of our key personnel are only putting in half a month effort toward the project. How do we enter that information in the budget period? Do we change the 1/2 month to 1 month without changing the requested salary or do we need to adjust our entire budget so everyone on the project team puts forth more than 160 hours?
The SF424 (R&R) budget accommodates partial months up to two decimal places (e.g., 2.55 is an acceptable value) and less than a full month (e.g., .50 is an acceptable value).
14. When we are preparing the type 5 non-competing progress report, should the person months presented represent the total effort on the grant or only the person months to be charged to the grant?
The person months presented should represent the total effort on the grant. This is because the total effort devoted to a grant does not always represent the actual salary that is requested.
15. Once we convert to the use of person months instead of percent effort, which of these two metrics should be used to certify time & effort to grants? Can investigators continue to certify time & effort with percent effort with an after the fact conversion to person months for institutional reporting?
It is an institutional level policy decision in how you capture time & effort reporting data. If your institution chooses to keep their current policy in place for collecting this data, that is acceptable and in compliance to the NIH policy standards.
16. Is there any specific guidance for calculating person months for individuals with VA appointments?
When dealing with individuals that have a joint University/VA appointment, the grantee should focus first on the University appointment when they are figuring out person months.  If VA effort is also devoted to the project, the grantee should continue to reflect the effort on a separate line item of the personnel section.

For example: 10% Univ. appointment would be listed as 1.2 mos on one line of the budget &   15% VA appointment would be 1.8 mos on another.  Or if this is a Modular grant then the grantee should reflect this information in the budget justification identifying his/hers appointment type (i.e. calendar, academic and/or summer months).

When dealing with the concept of total professional effort, it is still appropriate to reflect overall responsibility proportional totals as percentages of total.  This would be acceptable since you are potentially dealing with clinical, administrative, teaching and/or research responsibilities within each appointment.   However, grantees have the flexibility to manage this process in the manner that fits their institutional practice as long as consistency is applied.

With regard to other support for individuals with University/VA appointments, this does need to be reflected as calendar, academic and/or summer months.  Grantees should continue to reflect separately any University vs. VA effort devoted.